Okay, so why do you think the E-core load drops on the M2 at the very moment Logic playback begins?
The only thing Logic appears to be able to split is a few very specific audio instrument plugins — in fact, Alchemy is the ONLY one I can get to work on multiple cores (a maximum of three). The entire channel strip beyond that is always a single core.
We have no idea what it looks like on M1 CPUs, because we're only seeing those already under full playback load, unlike the M2 and M3, where we're seeing them at idle AND under load.
Interestingly, he doesn't show us this in either of his previous videos on the same subject, either. Both of which are built upon misrepresenting the M2 Pro as somehow inferior to the M1 Pro (which, as repeatedly stated above, is just a lie. He's comparing completely different product tiers).
It's quite possible that the M1's efficiency cores looked almost the same just before he hit play, and load on the e-cores did not actually increase from Logic usage at all.
Unless you've tried it yourself, I'm not going to accept any claims of M1 performance "seeming to work just fine" from a guy whose main claim to fame is three videos with click-bait titles based on a lie. (Incidentally, those three videos each outnumber the usual plays for his channel by 10x - 100x!)