...I changed my award F booking departing Monday outbound from LHR - PHX...to LHR - LAX (since availability opened up). The agent on the phone was unable to recalculate if there were any tax differences and told me they'd call me back within 24 hours...its been 48. No change fee was charged etc. When checking the booking online I see I'm booked on both outbound flights (LHR - PHX and LHR - LAX) for the day.

Do I need to be concerned here about being denied boarding? Getting a hold of North American BAEC can be a challenge with the time difference and the last thing I want is to be stuck in TXL due to a ticketing snafu while missing my TATL flight (PHX or LAX).