I think the decision is probably already 90% made. If they're ready to move on, nothing short of a good conference finals appearance was going to change that, so an early exit or second round loss won't change anything either.
And if they're not ready to move on, because the grass isn't always greener or, simply because they recognize the limitations of the roster (both its construction and its health/stability), an early exit also doesn't change that. But no Ben gives them PR cover with some of the media and WIP crowd.
Putting on the Negadelphian hat: the Sixers are never going to win a championship with this owner, this coach and these two players together, whether due to the impossibility of truly fixing the rest of the roster or health issues. In that sense changing the coach might be worth a shot. Of course if that doesn't work the only remaining step is trading one of the two stars, especially if they're still saddled with cap $ from some of these other guys.