After this, running "sm_l4dhooks_detours" in the server console has to produce output, and it should include something for the grenade throwing plugin.
I ended up replacing my sourcemod folders, even though I had the exact version that was released and they seem to be working again. The only issue is how my bots tend to not do much with hordes still with car alarms. They do throw molotovs at hordes/events, but rarely a pipebomb.