I asked a question and after a second realized it was better for programmers, so I deleted it and then asked it on programmers. Would it have been better to vote to migrate it or is it irrelevant? The question is here.
It depends I guess. If you see that early, delete it. If you waited some time, migration will be better as it will leave a trace on SO for followers to find the new question.
If it is already answered : migration is mandatory so as not to lose the answer.