It's an interesting theory. However, Samsung has already started to roll out One UI 9, which is built on top of Android 17 a month ago, so their clock has already started ticking.

I'm not familiar with the concrete wording of the regulation, but I would wager that the all the customization layers (like "One UI") that OEMs put on top of AOSP is the component for which the update clock should tick, and they should be unaffected of an underlying open source component (AOSP) being released.