Yup. You can absolutely draw a direct line from the emergence of New Atheism/"Rationality" as an online social movement in the early 2000s, and contemporary neo-reactionary politics (including the alt-right). There's a particularly close ideological link between the Hitchens/Harris crowd and the kind of "anti-feminism" that fueled Gamergate and the rise of Trumpism, as you say. Not everyone who was involved in that stuff gleefully slid down the slope into fascism, but those who weren't amenable to that kind of thing had largely abandoned the "movement" by 2012 or so. This is a pretty underappreciated piece of recent cultural history that lots of people who weren't Extremely Online (and moving in the right circles) in the early 2000s-2010s frequently forget about.

Again, I'd except Dennett from the atheist-to-fash thought leader pipeline. His interest was significantly more academic/professional than that of the rest of them, and Breaking The Spell is a respectable piece of philosophy rather than a polemic (though I think it gets a lot of stuff wrong). It's no coincidence that he stopped appearing with the rest of the crew pretty early on.