While GTC 2020 may be dead and buried for the time being, that does not mean NVIDIA will be holding off on unveiling its Ampere architecture for long. While rumours are floating around that it will be Q4 2020 before we RTX 3000 series GPUs, NVIDIA may showcase Ampere GPUs as early as next month.
https://www.notebookcheck.net/NVIDIA-delays-Ampere-GPUs-until-Q4-2020-but-an-announcement-could-be-happening-next-month.458466.0.html