[Hizonner]

My leading guess would be that Pornhub made some technical change to what titles were allowed or promoted, for who-knows-what reason. One possible guess would be that they simply started to promote titles with more descriptors, or more uncommon descriptors, in an attempt to get an easy boost to search specificity.

The timing is wrong for SESTA/FOSTA, and if SESTA/FOSTA was the reason for Pornhub making a change, even in anticipation, then it seems strange for Pornhub to intentionally make a change that would tend to emphasize titles that would increase political heat.

[On edit: ... and as I said, the "professionalization" hypothesis might also have legs as something that happened in response to an ID crackdown... but that wouldn't have to be related to SESTA/FOSTA, and would have had to happen before passage.]

[higuidebot]

Definitely plausible but it underrates the changes in actual content. It's not just SEO and titling, it's actual videos that have "stepsis" etc. as themes.

[Hizonner]

You didn't measure the changes in the actual content.