When I use dry yeast, I simply pitch it without rehydration. While rehydration may be better, I've gotten great results without it. I don't see any need to add nutrients if you do rehydrate. When the yeast is produced, it's coated with nutrients so no further should be necessary.
And FWIW, S33 wouldn't be my choice for a wit. I've never found anything vaguely Belgian about it's flavor. Word is that it's Edme, a British yeast.