It’s a bit ambiguous, so you could be right, but I took it to mean that activation of the receptors was that active mechanism, regardless of cause. Psilicin is just the compound they’re focused on, and maybe it does activate them in some unique way that has this effect, but the summary didn’t make that clear.

If there are alternative pathways to activate the receptors they may be better suited to thereputic use without the psycadelic side effects.