MMA has to at least get a mention for most reactionary sport because of its current real-world intersection with the Trump admin, Saudi sports-washing, Ramzan Kadyrov, etc. Although obviously combat sports historically have a strong prole-streak, at least among the fighters themselves.

Otherwise most reactionary is probably e-sports (because gamers suck) or racing (with cars), since it seems to have a high concentration of rich people and inbred european royals.

Most proletarian is probably soccer, running, and maybe bocce for being so accessible.