It's possible Oregon regrets this for some reason I can't imagine, but a repeat of the opioid crisis isn't a realistic outcome.
https://amp.theguardian.com/commentisfree/2022/jan/03/us-dru...
There are always companies that will try to make bank in an emerging market, but the details are different than an entrenched company using their power like in the opioid crisis.
But there is certainly risk that it creates a new class of problems. But, people are doing clandestine treatment with psilocybes currently, so it seems unlikely that legalization will find new classes of issues or a higher incidence rate of issues vs relatively-uninformed clandestine use. If there is a concerning issue, we'd expect that we've already seen it, but perhaps underestimated it.