literally nothing about this makes sense, other than to benefit Dillashaw and the UFC's PR spin to justify canning the tiny man division.
1. HC wants to move up immediately to fight TJ
2. TJ wants to be a 2x weight champ
2. FW division is getting scrapped - MM has been released, and lower tier FWs have already been given their walking papers.
The only reason I can possibly see for this is that the UFC have decided points 1 & 2 make the PR nightmare of putting 30+ fighters out of a job much simpler. MM had no intention of moving up, which would have made canning the longest reigning champ in history - and his division - a PR nightmare. With Henry winning the belt and wanting the TJ fight immediately, then releasing MM; that made shit infinitely easier for them.
Henry wants to challenge for the 135 belt anyway, but TJ is becoming quite marketable...therefore, if they hold the final fight at 125, it's win-win for the UFC and TJ. If Henry wins - that's a wrap. He needs to go to 135 and they can market an anticipated rematch at TJ's 'natural' weight. If TJ wins, he's a double champ, becomes more notorious, and Henry can waltz on off to ONE if he likes anyway, seeing as his contract purse likely exceeds his worth at 135lb. They probably have little faith in him being able to make the same waves at 135. Two birds with one stone.
So even if TJ loses, it can be blamed on the weight cut, and the division is scrapped anyway, and Henry had already gone on record saying he wants the 135 belt next.
None of this could have happened with MM around as champ, and now that HC/TJ is at 125, they protect the bigger asset in TJ as he doesn't lose the only 'real' belt.
Total bullshit, side-blinding tactics, but that's Ari for you. The fight is at 125 to save their bigger asset in case he loses. He gets bigger if he wins, and loses very little if he loses.