Honestly, considering the... staffing changes the good ship Discovery went through over the course of the first season, the crew could do with all the hands they could get. But Notaro will be serving the Federation elsewhere in season two.
Tig Notaro attends the Casting Society Of America's 33rd Annual Artios Awards at The Beverly Hilton Hotel on 18 January 18, 2018. Photo: Kevin Winter / Staff (Getty Images)
Announced today by CBS, Notaro will guest star in a currently-unconfirmed number of episodes in season two as Denise Reno, Chief Engineer aboard the Federation ship Hiawatha. If it is an ongoing appearance, it seems that a few more Federation ships beyond just the Discovery and the Enterprise will be playing a part in season two... that is, if the Hiawatha is sticking around for a bit longer than the Shenzhou did in season one.
But given Reno's position as a Chief Engineer, she could potentially hop aboard the Discovery for a spell, since the ship could really do with some new crewmembers now that it's no longer running on the experimental spore drive. After all, technically Stamets - who is part of the science division as an astromycologist, not engineering - is currently the Discovery's Chief Engineer, due to the biological components of the Spore Drive (which, up until the end of the first season, literally included himself). He probably could use a hand from some actual engineers now the ship's back to just operating on a warp drive, whether it's Reno offering it or otherwise.
They could do with getting their Chief Medical Officer replaced at some point too... for obvious reasons. But hey, one step at a time, eh?