Unless Apple is just removing 2 efficiency cores entirely, which seems incomprehensible, then this is a totally new chip architecture where the efficiency cores have an entirely new performance profile.
I suppose it is possible it could be using the efficiency cores going into the A15/M2 paired with the performance cores from the A14/M1 - call it the "M1/2".
But honestly, I am struggling to see how "only" having two M1 efficiency cores is going to be a major drawback beyond battery drain and the larger case will allow for more battery capacity to help compensate for that.
And I don't think the 2021 MBP having an "M1X" and the 2022 MBA having an "M2" is going to be all that confusing since Apple marketing should be able to show the performance differences. The 2021 iPad Air had a "newer" SoC with the A14 than the 2020 iPad Pro did with the A12Z, but Apple made it pretty clear how the iPad Pro was the more powerful product even with the "older" SoC.
Why the crap is Apple de-branding its stuff? First the iMacs and now the Macbooks? Don't they know seeing the words "Macbook Pro" especially when they show up in movies and such is great advertising?
Or Apple is hoping their new design aesthetic - which seems to be slab sides - will be iconic enough that "you'll know it's an Apple product when you see it".