There is no way UFC is going to work with any other MMA organization in the world for some cross promotion, I can guarantee that.
Only way for Ngannou and Jones guys to fight in future is when Jones contract with UFC is finished, maybe after his next drug test fail or after beating his wife again.
I think you are right, PFL now has the most versatile fighters but we can not leave other MMA corporations because there is a ton of variety to choose from and with the recent match with Bellator the Bellator 292 I think that was against a former UFC champion Benson Henderson VS Usman Nurmagomedov that I think will somehow enter the UFC after he pulverized all in his division, but I really love to see him get into another division in the Bellator to get himself another belt, so he could be a two-time division champion in Bellator when he move to UFC,
PFL Challenger Series 2023 Quick Card:
Kendly St. Louis vs. Paulo Henrique 155 lbs
Jackie Cataline vs. Evelyn Martins 145 lbs
Denzel Freeman vs. Raiden Kovacs 265 lbs
Sanon Sadeck vs. Ali Omar 170 lbs
Source: https://www.tapology.com/fightcenter/events/95446-pfl-challenger-series-16
I am surely gone tired of these challenger series events, both in PFL and UFC's Contender series aswell, but it is likely a great shot to look for great candidates for both MMA corporations so they can segregate those fighters that have true potential from those that are not UFC caliber, MMA has come a long way and is truly evolve anything can surely happen and people getting a good eye in watching MMA now not getting bored because of a wrestling only fighter, but I can truly say people that are watching MMA now have truly evolved aswell or learned the MMA way,