That snippet from the Sydney Morning Herald is the first time I've seen the signing of
RTS linked with any salary cap exemption.
I've asked the question when it was first announced that he was coming back that union players being exempt would come back every few years but never actioned. It would annoy the powers that be and the other clubs if we registered his contract referencing it or applying for it.
Then after his signing Sua'ali'i signed with the ARU the NRL management and media when a bit nuts and exemptions came up again. The chances of us signing a current All Black is slim to none unless it's 100% exempt from the cap for the entirety of the contract and the owner decided to free up huge amount of money. Even then the money would likely be better off long term on development.
A player on the fringes of All Black selection or Super Rugby/NPC level is more likely.