What Do You Do When...
…you’ve sent a submission to twelve different venues and, in the ensuing long slog of waiting for an answer (for Chrise-sakes one since December!!), you’ve made many edits, changes, punctuation decisions, and added a couple thousand words since?
Considering the work load of slush-readers and editors, to tap them back with an altered piece before a call has been made just doesn’t feel like a good idea. Because I know when I was doing editorial work I would rather have a writer who did something like this tell me after a decision had been made about what they submitted. On an accepted piece it was all part of the editing process anyway. But a bit of a tricky situation on a reject.
I dunno. Somewhere along the way I’ve lost what little sense I was born with.
You felt confident enough about the piece in its original form, so stick with that until you hear something one way or another. In my experience, acceptance doesn't necessarily mean they'll accept your changes (which is REALLY frustrating), and rejection usually means that they just didn't feel the piece was right for them in general. These people are buried, and it's not their fault.
Unless it is a major re-write and you feel good about the submission, I would not bother an editor with a sua sponte re-write. What would their life be like if everyone did that? Makes you look flighty.