If you class the 3090 as a gaming gpu I haven’t seen anything reported for 2021 for gaming. If you are looking for work station gpu’s then I have no idea. The 3090 is really a replacement for the old Titan cards which were technically not aimed at gaming.
Given that the rumoured 3080Ti which seemed to get close to being released has now been delayed indefinitely I would think the chances of a 3090Ti/Super are even lower.
With the on-going shortages likely to persist through most of 2021, I wouldn't expect much - no point in launching new bigger GPUs while you are nowhere near meeting demand for the current generation and GPU generations have been about two years apart for the last couple of cycles.
What is next after the 3090 will be the 4090 but even if it launches in 2021, it'll probably be 2022 before meaningful availability.