Hot take: 26 year olds should not fuck 19 year olds.
It's not illegal, but it's still weird, creepy and potentially harmful and no amount of lambasting about "the problematic age gap discourse" will make it not true.
I find it preposterous that you're talking about "power dynamics" when the 25 year old in this situation, at the time, was a poor intern at The Young Turks (making $25,000 / year in Los Angeles) who has lifelong body dysmorphia from being overweight as a teenager. While on the other hand, the 19 year old in this situation was literally
spoiler
Michael Jackson's daughter.
I mean, if anything, the 19 year old had more power in that relationship. She literally had 1,000,000 x more money than he did, at the time. He was literally a broke-ass boy toy to her. Do you not get that? Does six years of age make up for millions of dollars? And a nineteen year old who grew up in that environment is going to be very, very mature for their age.
tl;dr: LET STRAIGHT WOMEN HAVE BOY TOYS.
She consents. He consents. They were both adults. They were both mature. They are literally still friends with each other, on good terms. Please don't fall into the negative side of being parasocial. This is not even something worth talking about.
This post was inspired by Hasan but is not about him, nor his specific situation. I'm not going to address your other points because they're irrelevant to this discussion which is about a topic much broader than that.
I mean, it kind of feels like you're trying to gaslight people that were in perfectly harmless and healthy relationships into thinking that they need to see themselves as somehow sick / dirty / impure / sinners. So yes, it could be harmful. If Christianity can have negative effects on people's view of sex, then secular over-policing and internet with hunts can have the same effect.