Apple has invested too much into Dynamic Island for it to go away any time soon. I see no reason it won't make appearances in non-Pro iPhones (next cycle?), iPad Pros (this cycle?), other iPads (eventually?), maybe even trickle down into laptops and displays at some point. Regardless, it seems pretty clear that Dynamic Island is not a one-hit wonder. Even if we eventually move all sensors under-screen, requiring cutout, I can see Dynamic Island morphing into something like Dynamic Amoeba: able to move anywhere on the screen and not be tied to any specific cutout location.
Regardless, Apple tends to prefer getting several cycles, and return, out of their innovations. Not uncommon to see them leveraging an innovation across several manufacturing cycles and platforms. It's both a means to generate ROI as well as buy precious/necessary time between marketable innovations. As some understand, innovation is not push-button (1, 2, 3 INNOVATE!). It takes time, a lot of trial and error, a mountain of money and some dumb luck. Thus, innovating in a way that is both marketable and profitable is an art very few have mastered. While not an exacting science, Apple seems to have done (and is doing) pretty well, in that regard.