this said, smith will not play for australia vs the lions because the aru will not allow it.
The ARU will allow it providing he's contracted to the Brumbies come selection time. As things stand, Smith's on a short-term, three month Brumbies' contract and he's due to return to Suntory for the start of their season. Moves have already been made to extend Smith's Brumbies contract, delaying his return to Suntory, making him eligible for Wallaby selection. I'd imagine Eddie Jones will be enlisted to persuade Suntory of the wisdom of the change.
That said, as someone posted earlier, Dingo probably wouldn't pick him anyway.