you don't seem to understand. Nothing has changed except a published arrival time. It makes no difference whatsoever to anything, except on time performance.
So what you're saying is airlines maintain two sets of schedules, one for the public, the other for ops? It's like maintaining two sets of accounting records, bound to create problems at some point. For example .....
Public schedule:
MEL-SYD 0600/0755
SYD-ADL 0815/1020
ADL-SYD 1035/1320
and, operational schedule for airport/ATC/internal operations:
MEL-SYD 0600/0725
SYD-ADL 0815/0955
ADL-SYD 1035/1255