Pantoja vs Merab is realistic. Illia would have to lose the belt and go to 145 for Merab to move up.. along with Sterling being nowhere near a title shot. But Merab vs Volk could be interesting. Though I'd like to see Umar move up to 145 and fight Volk.
Illia vs Islam is realistic. Belal would have to lose the belt or move up 185, for Islam to move up and fight for the 170 belt. But Islam vs Shavkat, Leon, JDM, Brady, Usman and Covington are interesting. Though I'd like to see Usman vs Whittaker and Covington vs Strickland, both at 185. I do not think Shavkat beats Belal, and I don't see Islam getting an immediate title shot at 185, coming direct from 155.. but there is a rumored Whittaker vs Islam matchup, which would be very interesting if true. I do not think Illia beats Islam, and he has 2 fights on deck at 145 currently, along with the UFC possibly signing AJ McKee, Aaron Pico and/or Mix.. who all could fight at 145 for various reasons if signed.
DDP vs Alex isn't realistic in 2025. DDP still has 3 more fights at least at 185, which if 2 of the 3 happen this year, then that's 3 fights for him in one year as a Champ. Alex has Anakalaev next, plus the possible winner of Jan vs Olberg after, and then the possibility the UFC signs Nemkov who returns to 205.. which would be Alex's next possible three fights. Not to mention a possible Alex vs Aspinal or Alex vs Jones, at HW fight. Though I don't think Alex gets past Ankalaev in March, and I don't think DDP beats Khamzat next.