I agree on Morrissey/Marr. It would be hollow. We all know they are different people now and too much spilt non-dairy milk. And it's not The Smiths without Andy/Mike.
I really don't see it happening. Which is unfortunate for the fans (my bias aside), history shows that things were considerably better in almost all facets of his career (post The Smiths and early Street involvement) when Alain was not only writing the bulk of the material with Boz supplementing the gems he was offering during that time, but was also there to pull M up on some things he needed to be pulled up on. A concept that is quite obviously lacking these days.
Never say never, but there is no chance Al goes back under the current circumstances (not that he's being asked). As the person closest to filling his management needs by default, I wouldn't let him... as his friend I'd accidentally close his fingers in the door to prevent it from happening (hey, what are friends for?!? lol)
In all seriousness, M's current band is of little interest to Al (personally, once Boz and Al were both gone, the band lost any remaining pieces of its soul). If he took on Al's current band and or did a short term reform of the YA band, I think he has mentioned he'd consider it. He would also likely still write with M if it was just those two
(which is what was in fact discussed when he first rejoined a few years back).