Meh, I wouldn't worry too much about it.
I'm not sure of the year breakdown, but some XB dashes have a red CEL. In fact, I'm working on an '07 XB-S today and it's CEL is red.
No matter, even a wet dumped Buell engine will have oil left in the tank because the tank is lower than the engine. Oil in the tank means you'll have oil pressure at first start up no problem. The crank has roller bearings so it's much less important than plain bearings that need a film of oil to suspend the rotating crank, like in a car.