There's no issue that needs to be solved here
You seem to be saying (explicitly and implicitly) that there is an issue here that needs to be fixed. But I fail to see what it is and what negative effects it is causing. Before you start talking about solutions, you really need to establish that there is a problem that needs to be solved.
What issue does locked-in votes cause? From my perspective, it doesn't really cause any. The answer got those votes legitimately and voters gave them to the answer knowing that they would be locked in. Edits unlock voting in part so that a significant change in the answer itself (either making it more up-vote worthy or down-vote worthy) can allow you to change your vote accordingly. If something external to the question changes, then usually a significant update can be made to (presumably) improve it and that will unlock the votes. If no such change can be made, then the votes should stay the way they are.
If you see an issue, then I suggest you start a conversation about the problem on Meta first before proposing system-breaking solutions.
Editing is for improving the post
Edit privileges are for improving the post. Full stop. If your edit is not improving the post, then you shouldn't be making it. Edits are not for playing god over when people should and should not be able to change votes.
As I said above, there is no issue here, and, even if there were, the correct solution to a problem with the system is to work towards fixing the issue - not to misuse an unrelated part of the system to create your own solution.