That something was; yes, and that would be the most obvious thing it could have been. I was just thinking that with how Tanya had misinterpreted people’s intentions in the first series is, and how those she thought were trying to kill her made no open attempts to do so or admitted to doing so while being killed by Tanya, introduced a flicker of doubt there — that it would be fitting with the themes of The White Lotus if we later found out Tanya and Portia were mistaken, that the ‘something’ was something else (say like they too expected to benefit from Mia’s and Alessio’s scam, given that they briefly crossed paths) and that like Armond in the first season, Tanya (and those she killed) died for nothing — that she (like Shane) had made the wrong assumption.

As in if there were not meant to be a flicker of doubt, why not have them admit to it. When Tanya had shot the others and was about to shoot Quentin, she herself a look indicating she may have been wondering the same thing.