Yes, you could, the WC would be wet vented by the lav. [I guess there is a point of view that it wouldn't be allowed, not because of what the WC drain is doing, but because of the idea that a horizontal wet vent should stay horizontal, rather than turn vertical again. That doesn't make sense to me, and I don't think the IPC wording supports that interpretation.]
it would be nicer to come out of the wye (going upstream towards the WC) and stay at 45 to plumb until you're in the joist bay. That might make lining things up in plan a bit trickier, but it would eliminate quit some bends.
Cheers, Wayne