Stranger things have happened, but I'd be shocked if we don't go back when the world gets stable.
Matt had often been asked for a 4th sim earlier and laughed it off because his job was too intense to support it. I see no reason to think the opposite will suddenly happen when he's back to work. In fact, it will not surprise me if the league sees a few days of sporadic sims as he has to acclimate to the working cycle again.
That said, I can certainly see a case where--if we did not go back when things change--we would lose some GMs for our slick-salesman ways. It seems to me the situation right now, however, is best served with a short-term shrug and a long-term wait and see. The worst case is that a bunch of people decide they really like this new pace and Matt decides he can support it. At that point, if someone despises four sims, that person is faced with the dilemma of whether to resign or not. No on wants anyone to leave the league, but we are all semi-grown ups. Folks gotta folk.