"Divergence is still very expensive" is quite compatible with "Divergence is less expensive than before".

Here's evidence (not proof) that Nvidia would remove the hard limit of warp divergence (or perhaps more "precisely", *a warp is always synchronous across its 32 threads with divergence"): https://developer.nvidia.com/blog/cooperative-groups/

I don't think it's misleading to talk about a "CUDA core" as a warp-wide processor, although it seems that Nvidia doubles the number (at least for gaming GPUs), presumably because of having both FP and INT pathways.