Then what do you think, pray tell? It's not going to be as simple as bringing him and having him be his character. He has to work into a storyline somehow. I wouldn't be so bold as to say I think he WILL debut aligned with AJ, but I do think it'd be the best possible route. At least, if he's gunna debut on Raw (rather than Smackdown). I certainly don't understand how it would "ruin him".
The Foley storyline seemed pretty perfect to me. Or having him debut from the crowd, or attacking someone along with vignettes as someone mentioned on the last page.
Either way, I don't see how introducing him as 'AJ's boyfriend/crony' would make any sense at all.
1. Nobody would know who he is. It wouldn't require any kind of skill on Ambrose's part, and wouldn't emphasize any of the things that he's good at which is what a debut should do.
2. He is a loner. He doesn't seem like the kind of person that anyone would be interested in having around if they knew him in the past, especially an 'innocent girl' like AJ.
3. For the same reason, having him debut as anyone's 'crony' wouldn't suit him at all. If he was seen to be working for anyone or even being influenced by anyone it would be a crushing blow to his character. Especially if he was working for the GM. He's probably the least corporate guy you could get.
4. They have already used the ex-boyfriend/friend from the past angle with Cesaro and Aksana.
5. AJ already has a 'psychotic ex-boyfriend' in Kane.
6. How could there be any possible kayfabe reason for AJ to know Ambrose? And if she did, why wouldn't he have been mentioned during the whole thing with Bryan, Kane & Punk, and why would he suddenly be willing to come and fight for AJ against Bryan?
I don't mean to shit on your idea, but it would just be completely illogical in every way. AFAIK
there is absolutely no basis for this and the only reason it was suggested was because some Batman nerd said that AJ reminded them of Harley Quinn. Whatever, people need to get over the idea because it really would not be good for any party.
Edit: The second part of your post would make more sense, but not for a debut. Like I said, nobody would know who he was. He would come out to crickets.