This is actually a pretty good and rational change both on in terms of generational naming and core type naming. ARM's generational and SKU branding always felt more confusing than Intel and AMD (and they've done their fair share of tricks with pushing older micro-architecture in newer product series).
In past iterations of Mali you could configure the cores themselves to have different ratios of units in them, especially at the low end where 3D was less of a priority than pixel pushing, think TV/video controllers vs gaming devices. That feature seems to be a thing of the past but most of the low end devices there will probably stick with older GPU families for area and cost savings, if the new features are not going to be used, why pay for them?
I am surprised they didn't offer a G1-Nano option for the their GPUs.