Did he mention as to why?Wil has said he doesn't want to play Wesley again. But that was like 5-6 years ago, that could have changed.
Plus in a comedy I could see him changing his mind on that.
Wesley Crusher could gain alot of depth since last time we saw him going off with the Traveler and coming back as a officer on the Titan in the deleted cut-scene that can become "Canonized" if they wanted too.
Having a engineering officer with "Traveler" level of powers would be a HUGE asset to any StarFleet Captain given what they can do.
Stuck in a different Galaxy; Wesley, get us home!