Looks like a nothing here. Mozilla is within their right to add features to monetize their product and provide clear opt-outs for users who prefer “how it used to be”.
Purchases are tied to an Apple ID, so using the same Apple ID on the new device should allow this. I’ve never had problems here even with in app purchases. (There is often an option to “Restore Purchases” for in app specifically to enable a previously purchased item on a new device.)
> In Apple's case I fully expect they will make it so that when you plug your Apple display into your laptop it also charges it since the charger is permanently connected to (or built into) the Apple monitor/display.