There are a number of rumors on AMD's next-gen Radeon RX 7900 XT graphics cards. Take it as such, rumors. RDNA3 would offer a significant performance jump thanks to the implementation of a chiplet design like the Ryzen.

It is indicated that the next AMD flagship would be the first model of the Radeon RX 7000 series to adopt such a design, which would consist of two GPU's holding 80 CUs each (5120 Shader Processors), these would communicate over an I/O die. pretty much what you're seeing with Ryzen. The GPU would be Navi 31 and could be 2.5 times faster than Navi 21 (RX 6900 XT). The leaker, Yuko Yoshida, mentioned that performance improvement would be even greater, based on RDNA3 and 5nm fabbing.

It's speculation of the highest degree though. Personally, I don't see multi-chip design working well for graphics cards due to reasons of latency, cache, and complexity. Then again, we never would have thought that Ryzen would work out so well either.  For now, this is a lot of gossip and hearsay though. As it stands the way I see it, now next-gen GPUs still aren't expected till the end of 2022 maybe even 2023.