I don't think Sean is part of season 2.
https://twitter.com/Jefftthomas/status/1013599700212207616
He probably just has a small role again like in season 1.
At least a guest appearance... His character is alive, and pretty crucial to the plot so I can't see them just leaving him out completely.
If it is a smaller role, he can move on to new projects. Better projects. Season 1 was a fun watch, but it wasn't anything outstanding (like Broken, or Frankenstein Chronicles, Accused, etc.). I will stop watching once his involvement is done though. There were a few pretty bad performances in the show that I just couldn't stand (Katrina Law, Elisabeth Rohm)