When a question gets reopened, it should get a bump. By the time a post gets reopened, it's often fallen off the main page. Reopening implies that it's a decent question that's worthy of attention, so it seems fair to try to get it some fresh eyes.
Not sure if this is a feature request or a bug because Jeff said a little over a year ago that this is the existing behavior, but I didn't see it happen when I reopened Mobile site allows me to bypass closed questions 15 minutes ago.