Let’s also remember that Anson Mount’s Pike is presumably headed to the Enterprise at the season’s end, presumably because him coming along for Discovery’s next step would interfere with canon.
That’s probably also true for Spock, although we haven’t heard anything on Ethan Peck’s character yet.
For the moment, Control gives Star Trek: Discovery that perfect opportunity, and presents a new foe for the show to ship off away from its start to begin a new adventure with few limitations.