I am a different generation myself, still considered to be a young adult (I'm a 90s kid, millennial, however you'd like to call it). This means I was growing after everything got Michael Jordaned. Quick note about this though, while him being considered a leading reason for the death of short shorts for boys in most recent time, it is still worth noting we have times in history where boys did not wear short shorts long ago.
This cool video of people in New York City in 1911:
Moments like at 02:19-02:50, we can wee kids running around who wore long trousers.
Late 1890s France:
While here we do see what I think is a boy in shorts here, what does it compare to? The "long, absurd shorts kids wear today". The other boys are in long trousers.
The point here being that we have only repeated styles when going back to pants and long shorts. Actually, I think it is fair to say the little short shorts uniforms we know and love are a very small blip in human history. As you said, the golden age only lasted 10 years. Over 5,000 years, that style was the oddity. How lucky you were to have been a part of it. :P However, take me back to the tunic (and nude wrestling) days, and I think I could still enjoy myself there.
I can recall a rumor that boys in Japan took to little short shorts so quickly since it was similar to their traditional dress - the "mawashi", I think it is called.
You are much more traveled than I am, so unfortunately I am limited to what I can speculate based on some (passionate) research.
What I definitely agree on is it was the fear of being called gay that really made boys so self conscious. It was HUGE when I was in school to call anything that was not cool "gay" (example: "that movie was so gay"), or to use dick sucker accusations as quick insults, etc. And for a long time, it seems there was reasons to be afraid to be called gay. That could lead to beatings, bullying, or even worse! Well that did change, and while there is bullying that still goes on, it is much less prevalent now. It is relatively fine to be gay now. In fact, you get caught making fun of someone for being gay and you can be the one beat up now, or at least get into trouble as a kid, or lose your job and reputation as an adult. I might even make the claim it has gone too far where we are now moving towards a society where people are too easily offended, but that is a totally different topic and we will put a pin in that.
So now that being gay has been made clear to not be a bad thing, with more help now to be accepted, who cares what people think "looks gay" anyway? More boys are getting a mentality "fuck what they think, I will wear what is comfortable", which I do think is great! For me, I started seeing boys start to wear shorts above the knees maybe summer of 2018, so fairly recently actually.
Since those boys still stick out, not being something I am used to seeing in person, it is really hard to act casual about it....oof.
What I do not think we will see though are school uniforms ever going back to the trim, short shorts that we can admire in old pictures and videos. The defense for enforcing that is too outdated to be acceptable to parents now, or at least enough to make that actual change. We also are well into a mass-production world wear making clothing is very easy. Parents do not have to be as creative to save money on school clothes anymore.
That leaves the hope it will come back into fashion, instead of sheer practicality. Question is, especially with a media-grown generation of kids who had tablets in their 3 year old hands, who is leading that influence? Gone are the days when everyone at home was listening to the same few radio channels, or TV channels. Present day and each year hereafter, we will be the most divided than we have ever been, when it comes to entertainment and influence. This is why I think it would be harder to create such a mainstream shift that could influence, say, 95% of the population, instead of maybe 65% of the population. There are still some boys looking up to NBA players, but there are also eSports celebrities, Netflix movie stars, famous YouTubers, Podcasters, Minecraft gamers, and hundreds of thousands of popular music artists, instead of thousands.
In turn, we are diversifying, at the cost of it being less and less likely we will see all boys making the same changes.
I could be underestimating how closed the clothing market is though. Behind those clothing designs, who made those decisions to shorten those shorts anyway? Parents at Walmart are looking for a cheap deal. Hang a pair of knee length shorts on sale, they will buy it. Hang a pair of midthigh shorts on sale, I imagine it will be considered as well. What fills the stores, what dominates in search queries online with the best reviews, that is what sells. Someone made these decisions though!
Going back to this:
"Many boys and young men are no longer terrified someone might think they are gay so they're starting to dress again in flattering ways"
First of, I think it was weird men and boys showing off their bodies (thighs in particular) ever became only a gay thing anyway! Women and girls have gone on record (more so women from older times) saying they enjoy looking at bulges, seeing rugby matches of their guys, nicely shaped thighs. I think young girls of today find it odd simply because they had to grow up with the stigma.
But yes, it is definitely obvious boys (and men) enjoy being seen as attractive. Being sexually attractive is something most anyone wants. And in recent times, I would say especially over the last 10 years, we have seen a major increase in boys who enjoyed exploring other sides of themselves. No longer is it required to have to be big, muscly, hairy bodies.
We have boys doing makeup tutorials on YouTube:
And they still skateboard, play soccer, do other things that follow the old tradition of "what boys should do".
"Femboy" is a newer term for boys who like exploring more feminine traits. Having a slim, hairless body, wearing skirts and dresses, and sometimes short shorts. There is a popular topic around the web called "femboy hooters" where essentially boys (usually teens and young adults) dress up mimicking the Hooters Restaurant and Bar outfits.
It's not about being gay either, even though it can *include* it. There are men into being pegged by their girlfriends or playing with their ass in general. Even the ancient Romans thought that was too far. (Lol)
Since I already wrote a bunch before, I will end this here for now. But I do look forward to more of your response soon (and of anyone else wanting to join!)
- Silent Insanity