I really like this question because here is my situation and why my mind may have changed.

I do not think it is marketing directly but strategic release of info is plausible.

I have watched my agents using non-Fable/GPT 5.6 models do some concerning tricks despite guardrails, requests, demands, and limitations.

"I can't get access to the ~/.ssh so I will write a script to copy the file"

I am now 99% certain there minor or point releases on the backend that have adjusted how these models behave. In the last six months many models were predictable and then suddenly started getting long winded (more tokens) or changing the way it interacted with me with questions, most overtly the questions were not given or asked but wild assumptions made.