Data point with a connection: Flew ATL-TPA-BNA today with BS fare, A-01 for both flights. Got to ATL early enough to get on an earlier ATL-TPA leg. GA said going standby (or change) would impact my TPA-BNA leg. She tried to figure it out on her terminal but it kept wanting to put me on an even later TPA-BNA leg, eventually called in and was talked thru the process. Was handed 2 new boarding passes, A-12 for the 1st leg and still A-01 for the second, original PNR was printed on both.