It certainly can't hurt. Anything you can do to protect the fermented beer from oxygen exposure is good. When you rack into the keg make sure your racking tube reached all the way to the bottom of the keg. This prevents turbulence and splashing which keeps oxygen off the beer.
FERMENTING: nothing, I'm slacking
KEGGED: Innkeeper, Dry Irish Stout, Velvet Rooster Tripel, Smashing Pumpkin Ale
BOTTLED: Dubbel, Kriek