As far as I can tell, Apple was never going to ban games built on Unreal Engine. Epic made it sound very dramatic, but it seems like that was nothing more than Apple terminating Epic's developer account (for ongoing deliberate violation of rules in the Fortnite app) which happens to also be the account they use to publish the Unreal Engine on MacOS. In other words, Epic wouldn't be able to publish signed updated versions of the engine on MacOS, at least without creating a different developer account. Unless I'm missing something here, there was never a real threat that all games using Unreal Engine would be banned.