In as much as anything said without the club confirming it, it makes sense.
Will would want to play for Wales regularly (now he has fixed his ties to that nation), and this move would be as good as it could get for him.
Even IF Wasps had him under contract for next season, I think they would release him simply because it would be the right thing to do. The same goes for Thibaud at the end of his contract. Such things are what they are.
I have asked this before, but I think there is another Cardall coming through? I certainly saw a (one year) younger brother in one of the A matches last year I think? Was it against Tigers towards the end of the season?