They did not know about his graphic bottoming vids on this Twitter alt. They knew about his Instagram photos of him in a leather jockstrap at Southern Decadence and showing a bit of buttcrack on a nude beach lying face-down. The Twitter-alt fucking and the Instagram vacay photos are two entirely different things, and conflating them under the singular title "social media habits" is disingenuous.
As he was a low-level staffer posting non-graphic content on his private Instagram account, I don't think their response is all that surprising. They told him to "tone it down," which is more than some employers would do, and that was probably more in response to saying he wanted to suck on a representative's fingers, if that wasn't a reel to close friends, than it was to his vacation photos.