The Miz vs. Dolph Ziggler match is reportedly a front
The idea is that by Ziggler superkicking Shawn Michaels, he’s actually disrespecting all of the legends. He’s mentioned Goldberg in passing in interviews, and it’s believed that Goldberg will take exception to this and come back to get revenge for the legends.
Paul Heyman is responsible for this, as Goldberg is one of the wrestlers that Heyman was in charge of, like Brock Lesnar and Ronda Rousey. Heyman is a believer in the “badass old man who comes back at random times”, like an old gunslinger, a role that The Undertaker has similarly been used in for the last decade. Goldberg has previously said he wants to ‘erase the feeling’ of his now-notorious match with the Undertaker at Super Showdown, and a match with Ziggler could do that.
A match between Ziggler and Goldberg has been kept quiet to the point that the internal lineup in WWE still lists Ziggler vs. The Miz, but the match was never the plan, and Goldberg always was.