It's a super non-critical bug. It's easily user bypassable. In my case with an HP laptop with Intel on-board audio, if I shut down with the headphones plugged in and start with headphones unplugged the sound stays selected to headphone jack. Even if I play with the volume slider. The fix for me was to plug and unplug the headphones.
The question, do I report it to alsa or pulse? I don't know who is responsible for output selection logic.
EDIT: After some googling involving the terms jack, jack-sense, intel, and intel-hda I found that there are several open bugs for Alsa that are marked in a non-dismissive way. Ex: https://bugzilla.redhat.com/show_bug.cgi?id=540402 ... So it appears Alsa is the right place.
I would guess ALSA. However, if that's not right, they can reassign it. Just go ahead and file it on Launchpad and use your best judgment. No one will bite your head off for filing it in the wrong place.