3-letter calls for all Advanced, Standard and FOUNDATION licensees..

[VK5TM]

I see AMC are overstepping their authority again viz:

Q: I am an FL, upgrading to Standard – can I keep my 4 letter callsign?
A: No – you must apply for a 3 letter callsign.

And from the ACMA website:

If you have a foundation, standard or advanced licence, you can apply to the AMC for any available three-letter call sign. 

You can also keep your current call sign if you wish, including if you get a new qualification (for example, going from foundation to standard, or standard to advanced).