It is true that afaik, every pislocybe species bruises blue, the problem is, could it bruise blue, contain psilocybin, but also be poisonous. I think the truth is that it is pretty rare for that to be the case or may even be non existent but I'd definitely want to get verification on that for my specific region before harvesting anything.

Also, as a general point, it is a myth that bruising blue always indicates the presence of psilocybin. For instance, many boletes bruise blue and don't contain any psilocybin.

Here's a picture of an intensely blue staining bolete that does not have psilocybin:

https://i.redd.it/waumic0mjh921.jpg