It seems like this is Adobe's problem. I don't know if throwing their customers under the bus was a sad attempt at fomenting pressure on Dolby to capitulate, but it's really scummy and a bad look for Adobe.
And yeah all the CS2 apps are still working fine in 2019 under Windows 10 even tho they are 14 years old.
Amusingly enough, archive.org has archived those downloads too.
I wonder if comparable technologies exist that are open, or at least free to use.
This just provides a big of speculation as to the cause. It’s probably right, still speculation.
And it doesn’t matter who is at fault to the end consumer. If I was working on a project and Adobe suddenly told me that I had to upgrade because the version of Premiere I was using was “illegal” then I would be pissed off. Luckily I’m in between projects at work so this won’t hurt me too much.
Seems reasonable that they don't offer those versions as a download anymore (I guess you could question if they should offer those old versions without that unlicensed content/tools now. But I mean, you opted in to use their Software as a Service products. There are great alternatives for (nearly) all of their tools these days.)