Re: Surviving Vulcan Elders.
If the Federation use Spock's knowledge of the future to its benefit, why the hell wouldn't the Klingons send their own emissary back earlier still to undo him and do even more to its own benefit.
Sending them back the same way as in STXI wouldn't undo anything in the Abramsverse, it would just create another branching timeline.
"Your advertising's just dandy. Folks'd never guess you ain't got a thing to sell."