I'm sure the answer is "yes" in both cases, but I wonder if they are actually fusing off perfectly usable sections simply because they don't clock well at a given efficiency target, or if they're fusing off the unusable sections, all to prevent old-school GPU lotteries, where defective portions were technically usable and could sometimes result in a card being faster than baseline thanks to an extra bit of memory or raster cores that aren't entirely defective.
I remember a time when certain ATI and NVIDIA cards were valued due to both companies having not bothered to completely fuse off/kill the defective sections, so someone could end up with a non-standard number of cores and memory that usually performed better than baseline. In rare cases, having the same amount as a card one step up but just clocked lower due to power issues (and the resulting deliberate OC'ing of voltage to make it match at the expense of energy cost).
A more recent example was with Ryzen; IIRC, AMD had an unintended CPU lottery during the Ryzen 2000 era where some partially defective CCUs weren't fused off, so people got Ryzens with a non-standard number of cores or memory.