Not only is it specifically discussed in the vehicle regulations (https://www.law.cornell.edu/cfr/text/49/571.103), it has specific SAE standards for testing (https://www.sae.org/standards/content/j381_202006/).
I don't know if any of them specifically require a certain number of presses or such - I've never had an "old style" knob climate system that would automatically turn the blower to max in the defrost position, though that certainly helps the process. But neither have I ever run into a vehicle where the functionality is actively hidden. Scan for the defrost logo, front and rear, interact with the proper controls. To remove this obvious behavior from a car randomly speaks to an insane level of disconnect between the designers (who mostly operate on the concept of change for the sake of change, because any change makes it look new) and users (who, generally, would rather things stay where they were).
I don't care if my car UI wins international design awards for Excellence in Minimalism (ExMn) or something. I care that I can use it to make the various systems do what I want, or put them in a sane "Automatic" mode that then does reasonable things with them. And, further, I very much do care that they don't randomly change on me between trips in the vehicle.