breaking them up wouldn't make any make sense for the writers like Zoe Saldana said why bother with their relationship if you are not gonna stand by it and further develop it in the sequel?
They also did give a lot of space to it in the novels and plenty of hints in the comics.
What novels? The four JJ novels that were contracted and written have never been released.
like someone already answered I'm talking about the Starfleet Academy series.
Those set up the background and backstory of Spock and Uhura how they started their friendship and then fell in love.
I've read somewhere that both the comics and the novels are somehow canon because the writers ( Orci said it) need to approve them to a degree and the novels cannot have in them anything that the writers don't want them to have. I'd say it's a grey area between canon and non canon, they're still interesting though if you want to know how they got together.