Best solution I could see to this type of censorship of apps would be to sell an APK of it on someplace like itch(dot)io or a different store of their choice if they already aren’t. Just give up and start pointing towards those types of places. Though, I would make a final update to those who bought the game on the play store to at least tell them what’s going on and direct them to wherever the app would be available. Even if they’re not updating the game, probably still something to at least consider.

Edit:

Looked up the itch page for it and top comment right now is pretty much saying they should either put the APK for sale either on itch or humble bumble, steam as a DLC if possible to do so, or am•zon’s app store. I personally think itch is the safest bet myself, but I’m also an idiot who doesn’t know what sites are better for that type of stuff.