The new feedback option for rejecting edit requests is nice, albeit a bit restrictive (though the new free-form option helps). But here's one scenario that I feel could do with being spelled out explicitly:
Sometimes people edit the actual code in a question to fix errors. The consequences of this range from insignificant to totally obscuring what the question was about or where the poster was going wrong.
Such edits shouldn't be accepted, naturally, but they could have a dedicated rejection reason, such as "code changes obscure the original problem" or so.