It doesn't ask any confirmation, but create new recordings.
This is what happened here: http://musicbrainz.org/edit/14481795
I swapped titles of tracks 1 & 2.
I got no question/confirmation for recordings 1 and 2, but new recordings have been silently created.
I did not change anything for track 3 & 4, but sill, new recordings have been silently created.