I don't see the bowls disappearing, theres too much money and sponsors involved.
What is happening thus far is the top bowls are getting converted into playoff games, but no bowls are disappearing.
If there is a split, I'd imagine the bowls will split too. The conferences likely keep their current bowl tie-ins for the most part, and P4 bowls go with the P4, and current G5 bowls would stay with the G5.
There is talk now of the PAC Rose Bowl slot moving over to B10. It won't disappear no matter the outcome.