I am all for it, as it always seems weird to me that they use arguably the best talker in wrestling in such a limited capacity. I thoroughly enjoyed when he was managing Lesnar but also managing CM Punk through the heel end of his championship reign. I think the mistake after that was just the way they used him. It was one thing to have him managing Cesaro. But having him manage Curtis Axel and Ryback.... it did nothing for me.
Heyman could pick up another client but it would have to be a pretty high quality one. I wouldn't want him stuck with someone mediocre. The problem is that a lot of the better wrestlers out there right now really don't need him as a mouth piece. Kevin Owens definitely does not. AJ Styles definitely does not. Jericho, the Miz.... most of the top heels at the moment really don't need Heyman.
If Joe were to be called up, which is unlikely for a while since he is the champion, Heyman would be a good fit for Joe. Nakamura obviously needs to remain a face and he doesn't need a mouthpiece either. Sure, his attempts at English aren't that great, but it hardly matters. Shinsuke communicates better with his presence than almost anyone else in wrestling in my view. So perhaps Roman Reigns would be a good fit if he were to turn heel.
Now, I am not saying Heyman can't manage a face, but come on, Heyman is much better when he is behind a heel.