It seems to me that Stack Overflow has an infinite amount of outdated questions that pop out in Google, the SO search, etc. I frequently limit Google search to the last year to get accurate results.
I know this is a frequent theme, but well, nothing has been done.
It seems to me that the only way of improving this situation is creating some way to specify the API or SDK versions regarding the question/answer.
I am aware this is done via tagging, but it's never enforced nor recommended to specify the real version of the SDK you are using. We have tags like [iOS] and [iOS-SDK6] but I really think this could be improved.
Always specify the SDK version on tags [IOS-SDK-6.0], replacing generic tags like [IOS-SDK]
I think this is a better approach than creating [version-deprecated] tag for instance, first, because you remove the need to edit the tags, second because the answer might not be deprecated to everyone - there is aways someone using an older version of the software.
According to the answers, this may seem to be an iOS-related issue, mainly due to the yearly deprecation of the code. If it turns out to be true, I would recommend a retagging.