La'an, Ortegas, and Number One will all leave the ship after their hearts are shattered by Spock. M'Benga will be his next amorous fling, who will resign from the CMO position because he can't face Spock anymore afterward. Scotty is in line after that, who will be promoted to Chief Engineer via romantic nepotism (and then also have his heart broken, explaining the relatively unremarkable relationship between them in TOS). It's all going to tie together brilliantly.