I see the benefit to this for Jack.. the choice of club is a bit strange, but take a look and you'll see that its really not that bad, even though strange...
He will not be first choice here any time soon because he is well off the pace. He will not get back into the pace by getting 10 or 15 minutes here and there. He needs to be the focal point/lynch pin in the middle of the pitch. He CAN be that, we've seen it. He needs to get back to that player.
Honestly, if he is fit, he would be one of the first names on B'mouth's team sheet... He is head and shoulders above everyone else in that squad (ability-wise). He needs to re-discover how to truly influence games. He will not be able to do that right now with our squad. Maybe Wenger sees him ultimately as a Cazorla replacement, and with Santi getting up there in years, let Jack finish cooking (and hopefully stay fit) and take Santis place next season, because I think this is Santi's last season as a focal point.
If he fails to stay injury free? Then sell him to whoever will buy him after this season. I dont really like Jack on the wings, i dont think his ultimate game is suited for that (square pegs and all that out wide). If he succeeds and becomes a stronger player again? Then he walks back into our team. He has the talent, he has the drive.. he just needs the health and the focus