It's not the same, obviously. Just revealing the traitor is not dealing with the traitor. It reveals the traitor, and the fact that it is York is the shock factor. But nothing has been resolved yet in terms of the situation. Shaka is dead (presumably), SHs still fighting Seraphims. It certainly isn't an ex machina. It's not like Captain Marvel coming in to save the day at the last moment when the situation is dire. Hell, even Luffy awakening Gear 5th can count as an Ex machina, because it brought resolution to a dire situation. It's ok to lose sometimes bro, just take the L.
I have seen it so much online that the term has lost all meaning lol .