Pretty sure one of the novels writers over in TrekLit said they were not allowed to contradict the Supernova and Spock going missing in the books.
This is true. It is understood that these events happen in the Prime universe as far as the novels go so they could not contradict it by saying Spock was around in 2390 or having Romulus around in that year as well. But they also could not reference his disappearance or the destruction of Romulus in any way because those storylines are owned by the movies. So the books have been stretching out the years prior to those events and hoping a new agreement would arise instead of just flat out ignoring such a major event. Yes, it was stupid, haha.
But now they can write about it all they want!