I'm not quite sure, seeing as Pope and Anderson wouldn't be pushed to the main event instantly, because they weren't main event players in WWE, they might be taking some time to get back there, to say the least Pope probably would, Anderson I'm still in doubt if he'd ever get back in because of his firing.
Angle on the other hand, I think it's quite sure he'll be going straight to the main event picture, if he ever chooses to return, that's up to him, but if he does, and Vince lets him return, I can't see him doing mid-card stuff, perhaps upper mid-card to say the least, because I'm sure there's a lot of people who would remember Kurt, and know of his past of beating up the guys currently in the main event picture, so I have a hard time seeing him not getting back to compete with them without the crowd seeing the whole deal that he's being treated differently because of his leave.
But that's only if they actually do return, which is something I don't quite see happening, seeing as two of them were released and Kurt left on his own, if they would've wanted him back, they would've tried already I'm certain.