It's the exact same shit, same principal mechanism, same task, Cerny even described it on his presentation as you say, it's just the fanboys who are scared as fuck to admin the PS5 GPU won't be constantly running at 2.2GHz (which is officially listed by Sony as "variable" anyway), because that would make the gap to XBX bigger, but it is what it is, bending/denying reality on the internet doesn't work on the actual reality itself. NV has the same sort of tech, called Max-Q Dynamic Boost, and one of their slides is the best illustration how it works:
80W GPU + 35W CPU = 115W total, but that power can be switched to 95W GPU + 20W GPU, so the same 115W total, but more powerful GPU if needed. But PS5 (and any laptop with AMD Smartshift) can also go the other way around as well, like 65W GPU + 50W CPU (for the sake of this graph), whenever the task if CPU-bound. So you can squeeze more CPU and GPU power out of the same 115W depending on the task then if the CPU and GPU were running at fixed clocks, the "Balanced Power" on the graph. it is as you say, a laptop technology, which is indeed used in laptops to save battery by providing more performance at the same power draw, and without needing beefier cooling as well, and that's also why PS5 uses it, to control the temps by operating at a fixed power draw, but providing more CPU/GPU performance than if the clocks were fixed.