Doesn't it just make sense that Iro is being given time at centre? There's every chance he'll get a few games (maybe more) this year and any chance to get a run will help. Fitz should have zero concerns about Talakai stepping into centre or second row (or lock...) without much time in either position during the trials.
If Talakai was zero chance of playing forwards though he would be much less likely to be named on bench. Of course he could still be, for whatever reason. But one of the stronger reasons (I think) is, he is being considered for forwards.
Looks like only one other team has named a best 13 centre on the bench, but all have named many bench forwards.
Fitz should have zero concern about Katoa stepping into wing but he is still named there. He shouldn't be concern Cam has forgotten how to play lock either.
All I'm saying as from the info we have right now this is something I see as a bit of evidence Sifa might be spending some time in the forwards in the year, perhaps sooner rather than later.