As noted, Sting was originally told by WWE that he would be used at this year’s SummerSlam PPV, and would likely be in a 6 man tag team match with Roman Reigns and Dean Ambrose, against the Wyatt Family.
Sting reportedly got himself into “ridiculously” good shape for SummerSlam, but was then told he would not be needed for the show.
According to The Wrestling Observer, one of the reasons why Sting might have been pulled from SummerSlam is because WWE felt there was enough star power on the show with John Cena, Brock Lesnar, The Undertaker and actor Stephen Amell.
It’s very possible WWE might hold out until Night of Champions to bring Sting back, since WWE has been trying to boost Network subscription sales by bringing in names like The Undertaker for SummerSlam.
It’s possible we could eventually see the 6 man tag team match involving Sting and The Wyatt Family, once Erick Rowan has been cleared to return to the ring.