Actually, RFK Jr. has for some time been well-known by the staunchest anti-vaxxers to actually be pro-vax. (But for some reason RFK Jr has been represented by the media, both mainstream and popular-alternative, as some kind of anti-vaxx leader. Wonder why that is?)

He's been considered a sell-out for at least 5 years among the anti-vaxxers who consider themselves the most "informed".

Nothing to see here really. Not news really and not surprising in the least, IMO.