Nvidia's response is interesting -
“NVIDIA is excited to bring Zstd support to game developers, with decompression optimizations tailored for NVIDIA GeForce RTX GPUs arriving in the second half of this year.” – Patrick Neill, Distinguished Engineer, NVIDIA
Could be taken 1 of 2 ways, New GPU's arriving in the 2nd half or the optimisation arriving in the second half.
Nvidia employees must all go to special training to sound as vague as possible.