If you are talking about the 2017 interview with Murray he references: Harris was definitely well known before that. Unless you are saying that
now he's getting to be famous.
I had already skimmed Ezra Klein's
blog post which Sam Harris references this morning. The biggest takeaway I got from that blog post was that Ezra Klein is basically fuming at Sam Harris here for basically fumbling into a discussion with a guy like Murray who is probably a little racist by most people's standards. But really in my view a lot of the stuff that Klein sees as definitive is just more bluster and comes across as obnoxiously sanctimonious, which really sort of does confirm the idea that it
is "forbidden knowledge" that Sam Harris is exploring (whether or not it is actually true and therefore can be considered knowledge at all). Anyway, I think that Ezra Klein is probably right here, but his blog post from this morning reads like a big long rant in my eyes.
I didn't read what Sam Harris wrote, but it just seems like more airing of dirty laundry in public.