I think I have some inside view on last year specifically. I was focused only on label releases and beatport since for better of for worst this is the best place to find all kinds of music.
I've checked almost every single release last year. Anything I didn't bough was just dumped from my brain, but I still purchased 1000 songs in 12 months.
So here are my thoughts:
Maybe some producers used it as a gimmick - I am thinking Ben Hamsley for example. But even if you check his first releases his music always had 90s vibe so I am more inclined to say maybe not, or he is going for that style only for a purpose.
Than you get some producers like Marc Van Linden who did only old school music last year and he has been around for a while so I don't thinks so either. It sure looks like passion, also I was very surprised Vandit where he releases was releasing some old sounding stuff.
Then my favourite DJ Darroo who moved from hard trance and dance to old school trance last year(I actually found him last year because of that) , again someone who has been for a while in the industry so I don't think he is making it as gimmick. But as they say in some studies with age people mellow and tend to go for less energetic and banging music - plausible explanation.
Surprisingly the two most productive ones in my opinion had DJ in their names which is not surprising at all, because this people listened or dj-ed that kind of music and it influnced them even in later stages of their careers. (Dj.Fili, DJ Darroo)
Another thing I personally saw old school producers like The Digital Blonde and Mac & Monday saying they are not getting chances to dj because they are overlooked. And we all know why, because old school trance is not popular, not even in the slightest.
In conclusion, I don't think it's a gimmick for MOST
of the producers, but a passion project. I urge everyone to check my compilation, I have the complete list with the labels names here in the forum and the compilation is very useful because it summarises all the trends of 2022. Btw most of the old school stuff went on the techy works and the old school selection from the compilation. I definitely found some labels I want to keep an eye on...