Remember, TRT is a dr. writing a script to get someone IN RANGE. Not 1200 ng/ml PLUS.
I'm on TRT because my levels were so low (150s). I also had (have) a kickass build, so it's somewhat an anomoly. My levels hopefully will reach what is average, around 600ng/ml.
UFC shouldn't allow someone to compete if they're taking bodybuilder type amounts. If they're on legit TRT though, I believe it's fine, as long as they're competing within range.