I’m not the most accurate and precise regarding the lore but for what I remember of TOS (that was my favorite series) we should expect Sulu being the next one, then Bones should be in the cast together with Kirk later. Seeing that every one that will not be in TOS is now in Gorn hand’s I think we already know why. I don’t think it’s a coincidence
Oh that was the same doctor? Never connected the two. I was thinking also about Ortega. Sam disappeared in TOS until he died so maybe he got traumatized from the incident.