IIRC, Scotty decommitted from MSU and was uncommitted for a period of time. Not saying Tennessee didn't pursue him as an MSU commit, and that led to him decommitting. But he was essentially "on the open market" between commitments.
For the record though, I think there is a difference in staying in contact with a committed recruit, and actively pursuing a committed recruit. You never want to terminate contact with a recruit you'd like to have, especially one who commits as early as SH did to MSU. Coaching changes, NCAA violations, etc., can lead them to opening back up. Schools that continue to maintain a relationship will get the first call most times.