John Gruber ( and only him ) [1] suggest Epic was making things up when Apple would terminate Sign in with Apple on EPIC's App. While I dont fully side with EPIC on their case against Apple, on this issue alone it was clear the fault was on Apple [2].
And imagine you are in a dispute with Apple on this matter for longer than 30days without resolution, the time your iCloud would keep your backup before it is completely wipe out due to Account termination.
[1] https://daringfireball.net/linked/2020/09/29/epic-games-unre...
[2] https://twitter.com/TimSweeneyEpic/status/131179493779778355...