I’ve seen this happen a bunch of time now that people just ask a question and it’s deleted a day or so later. Do they delete the question themselves, or is that some automatic thing? If they do it themselves, why?
*edit*
Thanks for the great answers so far. Very insightful. Please keep them coming, I’m curious to more points of view.
Probably multiple reasons. If it’s a throwaway account they may want to cover the tracks. If it didn’t get a response they were looking for, they may delete and recreate to avoid the double posting rules. They may have posted on the wrong account, or maybe the answer was so obvious they were embarrassed.