The new sensor cycles usually combine load size sensing with soil sensing and create much more flexible settings.
Usually the cycle can select number of prewashes, post rinses, time and temp of the main wash aswell as final rinse temp.
Given the options can add anywhere from no water up to several liters, my best guess is that high temp forces a 4 fill cycle while sanitize forces a 5 fill cycle (2 post rinses before final rinse).
But if these are anything like previous machines, the theoretical maximum of fills is 7 I think (3 prewashes, main wash, 2 post to rinses, final rinse) while the minimum is 2 1/2 (main wash, purge, final rinse).
So Auto could still sense that up.
Also, Auto can certainly select a main wash time, so it could potentially run a short but hot wash.