That’s Apple’s prerogative after banning a developer who has violated their contract with them. Otherwise you could have shady developers just create numerous of legal entities to effectively brute force their way on to the store, and Apple would be unable to respond.
This case is less about monopolisation and more about inequality between two parties when settling a contract. Nothing stops Epic from making an Epic phone and doing the same.
I'm not fan of Epic however if the court rules Epic as right, we are about to see an important precedent to a less monopolized market.