I think right now there's a bit of a sour taste around the way thing transpired - unlike Abbott he apparently hadn't given any indication that he was thinking of going Kolpak, and he let them know in an email rather than in person/a phone call. But when Amla, De Villiers, Du Plessis, and Duminy (all who are a similar age) decide to call it a day, I think enough time will have passed for everyone to be able to put this behind them, and it would be madness for CSA not to try to get him back.
I agree, but he has had the misfortune of playing at the same time as some very good batsmen - it's tough to break into an ODI batting line-up comprising De Kock, Amla, Du Plessis, De Villiers, Duminy, and Miller. And he was injured when there happened to be an opening in the test team, which resulted in Van Zyl and Bavuma being selected.