Roger, sorry to hear of your hassle.
In the UK the "waiver" memo came out about a week and a half before the "change tyres" memo, both in February. I collected my car in March and it has summer tyres on, I wasn't asked to sign the waiver.
Even though I haven't got the issue I have arranged with the dealers to change my tyres to all season ones in November.
As the memo related to RHD cars it should be applicable to Aussie cars and Aussie customer services should push this.
The Macan is a good choice and I looked at it but personally didn't like the look of it and was smaller inside than the 43, was a bit worried about carrying on with my order as I was aware of this issue but I am 100% glad I did.
2017 GLC AMG43 premium plus, night pack, leather, intel lights, 360 camera, side steps. = sadly gone
Now GLE450 Premium plus, Selenite, Black/White Nappa leather, Tech plus pack, Driving assistance pack, Tow pack, Off road pack, 22 inch wheels.