Lawless and Andras were talking about playing that character on twitter, which concluded that Andras' people would talk to Lawless' people. But that was when S2 concluded, and no word since, except that Andras is excited about a casting spoiler.

Speaking of Doc: https://www.space.ca/wynonna-earp-season-3-photos/
No big spoilers, but one picture from what looks like it's going to be a fun first two episodes.