There have been rumors on Dolph Ziggler being unhappy in WWE for some time but now the rumors are that he's looking to leave the company when his contract is up in a few months.
During a recent episode of MLW Radio, available at this link, former WWE creative writer Court Bauer commented on the rumor, referring to Ziggler leaving like John Morrison did. Morrison now works for Lucha Underground as Johnny Mundo. Bauer said:
"Dolph's deal is up in a few months and he has indicated informally that unless he gets a big push, he may leave like Mundo."
Source
Yeah, this ain't the first rumor of DZ leaving the company soon, so... Let's see how it turns out this time.