It's interesting that they will only have it on the surface through July 7, especially since GPT-5.6 will presumably come out soon as well.
Of course, it's possible that Fable remains drastically better than 5.6, but to whatever extent Fable is the true frontier (if temporarily)... it makes me wonder if external commitments on compute put a hard deadline on how long they could run Fable on the subscriptions.