I've never dealt with a hugel bed, but I would imagine there's any easier way around this. Perhaps build the actual bed in fall, give it the winter (which tends to be wetter, guess it depends) to season itself, then plant it the next season. Like I've said, no
experience to back it but it sounds reasonable
enough.
With that said, a drip system is cheap enough, figure $14 for the 1/2" tubing, $5 for the emitters, $3 for the coupling to a garden hose, that it can't hurt to try it.