Billy made a good point on the first page. Punk and Bryan never encountered each other when they were in ROH. They were there at the same time but there wasn't any heat, or friendship, or anything like that. The Kings weren't even thought of in that era either, so obviously these two have no reason to be associated with them, other than the fact that Punk and Hero are actually really good friends. But WWE wouldn't acknowledge that.
And anyways, if the WWE brought them in, they wouldn't label them as an ROH stable. They probably wwouldn't even label them as an indy stable, because one thing would lead to another and WWE's domestic fans would go google them and their history, then they'd stumble upon ROH, and then people would begin to tune into ROH more and more, and so on and so forth.
It's an idea that's been done to death. Most people who even suggest such an alliance are those who know very little about ROH anyways, for some odd reason. Not every indy wrestler belongs with another indy wrestler. It's like how TNA created EV2.0... It was a nice idea, but just because you have a bunch of former ECW superstars on your roster, that doesn't mean they all have to be in one big stable. Their styles begin to clash and it falls apart.
And given that only a small portion of WWE's fan base is aware of ROH and what they're about, it would be extremely ineffective to form a stable of ROH alums. And anyways, if you were to go that route, why not just make it Punk, Bryan, and Bourne? Use three established stars to make a stable that the common WWE fan will be invested in. Do you think the common WWE fan is worried about Hero or Claudio, and do you think they'll know why they're debuting, teaming with the two world champions?
It's not a good idea quite frankly. Punk and Bryan need no allies, and it's best for Claudio and Chris to find their own way as well, whether it be in singles competition or as a team still.