When I worked on jailbreaking tools for iOS devices, we routinely held onto multiple 0-days, waiting for a major iOS release to ensure compatibility.
While I know there may be reasons to disagree with that practice, I think it would be a major stretch to say that it meant iOS suddenly had a backdoor.
While I know there may be reasons to disagree with that practice, I think it would be a major stretch to say that it meant iOS suddenly had a backdoor.