I bet someone at Google would be a bit surprised to see someone jumping to legalese to act like this...novelty...is inherently due to the preview status, and based on anything more than a sense that there's no net harm done to us if it costs the same and is better.
I'm not sure they're wrong.
But it also leads to a sort of "nobody knows how anything works because we have 2^N configs and 5 bits" - for instance, 05-06 was also upgraded to 06-05. Except it wasn't, if you sent variable thinking to 05-06 after upgrade it'd fail. (and don't get me started on the 5 different thinking configurations for Gemini 2.5 flash thinking vs. gemini 05-06 vs. 06-05 and 0 thinking)