Salt is the important thing to apply ahead of time. It's also the only thing that will actually penetrate the meat.
The science (google "the science of rubs") shows that the size of the rub particles, even ones that dissolve, are too large to penetrate solid muscle meats EXCEPT salt...so rubbing the night before doesn't really have any advantage...
I usually pre salt my meat the night before, use a "salt lite" or "salt free" rub which I apply while the smoker is warming up.
That being said, it certainly does not hurt anything to rub the night before.