I think you are totally right about the Mithras priest class, but I don’t think they are being newly cultivated. I think they have been continuously active since that time, and are now revealing themselves.

Maybe there are more of them than we know, and they are trying to use their power to become mainstream so they can be what they are openly.

I think they overestimate people’s willingness to go along, and I think whatever occult power they have depends on them being marginal, rather than mainstream.