Nice observation Gary.
I'm not sure if the guys at Pinkfroot have picked this up, but the change in flight codes seems to have resulted in all Tigerair Australia flights flying without flight information.
As was pointed out by Gary, the ICAO code has changed to become TGG, however all flight numbers and their respective flight routes have remained the same. The IATA code has not changed.
For example: TGW313/TT313 operating BNE-ADL has now changed to TGG313/TT313, and is still operating the leg from BNE-ADL. I do not believe that there has been change in departure and arrival times.
Similarly, the ATC callsign for flights has now changed from "GO CAT" to "TIGGOZ"
A thing to note however is that Plane Finder's filters still show that there are still Tigerair Singapore flights flying bearing the ICAO code of TGW.
May I apologise in advance; perhaps this post better belongs in the 'Plane Finder Data' section of the forum.