A lot of prominent film actors that wouldn't typically be thought of as willing to do TV have been delving into some pretty interesting limited run episodic projects, anthology series and such. Look at, say, True Detective.
Should we get a show to follow up on Alien: Covenant's cliffhanger, I don't imagine that the narrative would run longer than a season. Think of it as being like a miniseries. I could absolutely see Fassbender reprising his role for a project like that.