While anything is possible, I think it's very rare, especially when people are doing the kind of work on herself that Kerry is/was.  I think if people just kind of drift away, they could go back, but then they probably didn't really leave in the first place.

There really can't be a Rawat "splinter group" because it's a personality cult, and without Rawat there is no cult.  True, his brother broke away and is the "other" Perfect Master, but he mostly just does the same thing Rawat does, more traditionally, has no real following in the West and doesn't really propagate beyond East Indians or people with a Hindu tradition.

After you read "Dry" I recommend "Running With Scissors" (soon to be a major motion picture.)