That isn't really a thing they can do for already shipped games, unless your game has an online component with dedicated servers and you need to update unity on the server side for a security fix. Most games don't upgrade their engine post launch, unless they are a live service game intended to get constant, significant updates for a long time.
The goodwill has been burned and now everything needs to be contractually spelled out.
Or, for a good number of people, they can bail out to Godot for 2D or Unreal for 3D or consoles.