There are a LOT of things TFP should be praised for, having made this wonderful game which was something that the rest of the market failed to offer, but "cause and effect" is just not up their alley... I mean, this is the "20, 40, 60 gates" all over again, and a lot of people have been asking for area & POI scaling from the beginning for very specific reasons, which I don't believe they endorse or understand. And as this will require a balance do-over, it certainly wasn't a necessary step.
I really, really hope I get proven wrong and A20 greets us with a great zone system that emulates a "living, breathing world", with, for once, sublime gating, which will achieve prolonging gameplay in a more intuitive way that the players won't even notice.
But for that to happen, as you said, leveled zones have to apply to enemies as well. "That's why they are building the GS scaling" one might say, but personally I can't imagine how they will achieve smooth player progression, that doesn't lead to gimmicky player behaviors like the ones
@Solomon mentioned, with GS scaling enemies and items like it does now, with its outdated formula, while also governing the difficulty of the BM (which is the only part of the game that actually needs level scaling) and, finally, the current death penalty, spawning and item economy states. My guess is that, in the end, they will have to tune everything separately all over again, or leave the game in a transcendent "just fine" state and move on to the next. Many steps forwards were made towards that direction like the DP introduction (which is still mostly inconsequential) or the injury system, but again, as I see it, a lot of steps backwards were made as well, like e.g. degradation going away, and even in areas such as spawning (e.g. sandwich-ing, which was gone on a whim).
Anyway, it's a fun ride which yields lessons for everyone involved and I wish the final result is a great experience, for both the sake of my own entertainment as well as the success of their next game.