That would be logical as paying upfront would be a big waste of...

That would be logical as paying upfront would be a big waste of cash (but if I was telstra that's exactly what i would do - bid a conforming bid, and also throw in a non-conforming bid sweetening it with upfront payment or something similar).
lets not forget the big picture here tho - 1. in order to run any mobile network - dark fibre is key (which TPM has an abundance of), and 2. with 5G, one would be looking to stream 4K/UHD quality seamlesslesly / do VR etc on the move.....that's not far away, but it's not exactly just around the corner either...

TPM will get their piece of 5G... i think the bigger short-term/medium term question is do they make a play for Vocus Corp/Vocus assets (due to the fibre assets they have).. or they don't cos there is too much unnecessary overlap.... 5G is all about a balance between fibre & towers IMO...