I loved that Nimoy was on hand in the 2009 film to usher in the changes and pass the baton, as it were. However, his STID appearance did nothing for the story and it just seemed like a trapdoor for nuSPock to keep asking how things turn out. I really felt that, if there wasn't a really important reason for Spock Prime to be there, he shouldn't have been. And he didn't tell young Spock anything that really helped. Unless he needed Spock Prime to say "punch him REALLY hard!"
Now Nimoy is gone. No reason to squeeze him in posthumously. The dedication is a great idea, other than than, since he can't really figure into the plot (being dead and stuff), leave him out. I agree, enough fixation with the past. Move forward.