Preterist heretical?

I had a retired pastor talk to me today about going to Colorado to correct a false and evil doctrine that has started called Preterism.

Obviously, I understand what Preterism is, that is not the issue, but the issue is, should this be considered as a false and evil doctrine or since it is not related to salvation, and to interpretation of the Revelation, then is it right to go around to churches to correct this

He actually used the word "heresy" in relation to the doctrine.