YeOldeProp,
The union paper had an article about that. The guys returning from service in the Reserves or Guard don't generally need the whole new hire training class. They requal fairly quickly, may get some IOE-training with a check airman, probably a sim check, and they're back out on the line. The article said that SWA is much, much quicker about getting guys back onto the line than many other carriers.
Newhire training is newhire training. I've heard of ONE pilot who was out on an extended medical who had to redo the whole thing (newhire FO training, then captain upgrade training, don't know if he did or what would be required to regain his check airman qualification), but otherwise the newhire classes are 24 new pilots. Sometimes plus two instructors, but they're in addition to, not in place of, newhires.
Anything's possible, but I don't see ANG/Reserve returnees going thru newhire training. Too much of it is stuff they already know and would only need a refresher on, far less time in the classroom & sim.
Cheers!