It could go that way,but the problem it tops out at 4096 shaders according to the rumours,unless they are wrong and it has far more shaders. Adding more memory controllers would be easy as Navi 32 is still a chiplet design AFAIK.
But I can't see how Navi 32,even running at higher clockspeeds,could beat a 4608 shader RX6800XT by a decent amount? Even if it ran at 3GHZ consistently,ie,about 35% more than an RX6800XT,it would barely be 20% to 25% faster overall(at best). In that sense it would make more sense to release a 4608 shader version of Navi 32 with a 256 bit memory controller.
The RX6800 only had 3840 shaders,so a fully enabled Navi 32 would have more shaders and a higher clockspeed. So it could be quite possible that a 256 bit memory bus is attached to a Navi 32 based RX7800. So if we went that way:
1.)RX7900XTX 24GB - Navi 31(384 bit memory controller).
2.)RX7900XT 20GB - Navi 31(320 bit memory controller).
3.)RX7800XT 16GB - Navi 31(256 bit memory controller).
4.)RX7800 16GB - Navi 32(256 bit memory controller).
5.)RX7700XT 12GB - Navi 32(192 bit memory controller).
6.)RX7700 10GB - Navi 32(160 bit memory controller).
7.)RX7600XT 8GB - Navi 33.
8.)RX7600 8GB - Navi 33.
If the RX7800XT ends up being a 4096 shader Navi 32,it will be a small generational increase. It could happen,but I hope it doesn't because it will be as bad as what Nvidia is doing now.