TL;DR: Suggested edits shouldn't unlock votes on a post until they are approved.
Votes on posts get locked in after a certain time. The reason given for this behavior is to prevent tactical downvoting.
There are known loopholes to get past this. Since the post being edited unlocks the post's votes, a user can edit the post for the express purpose of unlocking their vote. While frowned upon, there isn't a real mechanism to prevent this, other than the reputation threshold required to edit posts (we just have to trust that users with enough reputation to do so can be trusted not to abuse this loophole).
However, it appears this loophole can be exploited through suggested edits also. The suggested edit doesn't even have to be approved! Thus, anybody can throw a junk edit at a question just to unlock their vote.