It will probably be the same as when everyone left Digg and went to Reddit. It happened because of what Digg did to itself, Reddit was just in the right place at the right time.

I don't know if Voat ever had a chance, but if it did, that opportunity was lost by being unable to scale when there was a major incident over at Reddit. Reddit seems to be more of a slow-motion trainwreck now, so perhaps it won't be as much of an issue. But if there is some other major event (like say, banning The_Donald), if this site can't handle the traffic it's going to be a lost opportunity.