This is 100% targeted at bleeding indie game developers dry in hopes of taking some of that sweet viral cash from devs like the one who made Vampire Survivors. They see that indie devs are charging $3-5 for their games, and so they aren't hitting the $200k threshold unless they go viral, so Unity is charging by install, not just by total revenue. I hope that the ESA or other interested groups take legal action against this retroactive greed.
After seeing the way WotC handled DnD and MtG, and the way Musk has been dragging Twitter through the shit, I really believe that shareholders are trying to take what they can while they can and peace out. No one is looking at the long term anymore. Everyone just wants theirs, fuck everything else.