The future for WSOs is ISTAR.
SDSR10 projected RJ and Sentry as the only future core assets. Now we have both of those for at least 20 more years. Sentinel is being retained. Shadow fleet increasing by 60%. About 100 more RPAS crews are needed, plus 24 P8 crews - that's 48 WSO's on that one alone.
I'd say recruiting now is essential, but starting up a training pipeline is going to be difficult.