I would suspect we will see a split. And in a sense I think we already are, which complicates the matter because we also have this idea that styles have names, and the name stays. When BJJ broke off it got a new name, when Sambo broke off it got a new name, when Judo broke from jujitsu it got a new name... This happened in other styles, we got tons of flavours of karate.
In BJJ there are schools that are very much MMA based, some that are very much sport BJJ based, some that are self-defence based. Some are all gi, some are all no-gi. Standards in rank are diverging.
It's all good though, there is room for all of those things. Including schools that try to do a little bit of everything. No "style" needs to stay unified and under a single set of guidelines and curriculum. As long as it keeps the core ideas, which are fighting to submission against a opponent trying to do the same thing to you it will remain an amazing style regardless of the schools particular focus.
And if IBJJF rules start going crazy, another organization will pop up. They already have, there is IBJJF, FILA, ABDCC, Grapplers Quest, etc.