Only monetized games have to pay. If they stop selling the game, they shouldn't be affected anymore.
Also
Does the Unity Runtime Fee apply to pirated copies of games?
We are happy to work with any developer who has been the victim of piracy so that they are not unfairly hurt by unwanted installs. (source)
Oh dear. The only option left will be to pirate it... And in the new model, the dev might have to pay unity even for pirated installs.
Only monetized games have to pay. If they stop selling the game, they shouldn't be affected anymore.
Also
"trust me bro"