I mean, Andreeson has always been an ancap, I knew people who worked with him in university. He didn't change.
For much of Medium's history, the VC representative to the board was Ben Horowitz, of Andreeson-Horowitz. Currently the VC spot is held by Kevin Thau, of Spark Capital.
I agree that Medium is better than substack, but I get why people don't like it and I'll generally choose content on other platforms when possible. Their union busting activities alone are enough to stay away