MMA is an absurdly fast-moving and unpredictable sport. While a certain amount of knowledge and education can go into predicting the future of the sport, there's also a fair dollop of luck, or lack thereof, involved. Fighters get injured, fail to make weight, lose what appear to be sure-fire wins, or - as is often the case these days - simply decide to stop fighting.
All of that is to say, predicting the future is about the same as predicting the weather; you have a good idea of how things will go but every now and then nature throws a spanner in the works. That's not a bad thing though; the mercurial nature of the sport is what keeps it fresh and alive.
If you'd tried to play the guessing game one year ago, would you have predicted that Daniel Cormier would be Heavyweight Champion? That Tyrone Woodley wouldn't have fought in a year? That Cris Cyborg would still be champ? Well that last one was a fairly safe bet but the others not so much. It's certainly been an odd year for UFC with Champions clearing out their respective divisions, leading to divisive "Super Fights", poor buy-rates, inactive fighters, and more interim belts than you could shake a stick at.
From now until July 2019 looks to be just as wacky, so let's see who will be sitting atop the throne(s) by then.