Oh man Revo, this is a toughie >< And I think my general answer right now would be that I won't advise anything too risky for managers. I'll try to stick to the tried and true skills that we know are important and will continue to be important, PA/OD/RB and so on. Before we see the updates effects on the shooting skills and SB. So the only managers I'd currently advise to really train any of SB/JS/IS/JR maybe even DR/HA are guys who don't have much left to work on.
I could see maybe a fringe prospect deciding to take a risk and train SB, but it'd be just that a risk and I'd make that very clear that not only might he not wind up being useful to the NT he could wind up being not very helpful to your own team as well. Which is something I try very hard to do, I try to advise managers in training directions that will help their own team even if their player may not achieve NT status.