Every process name is basically a marketing a gimmick. You could sort of use the previous names as a ratio to get a general idea of uplift but that isn’t really accurate either. To further confuse things Intel’s naming scheme had bigger nm values but is a similar size to lower numbered names from TSMC.
I would guess there is no way in hell they are going to stop making GPUs becuase GPU development leads directly to their ability to make better AI accelerators. I could see them backing off of CPU prodiction before cutting out GPUs.