Information about AMD's upcoming Navi 23-based Radeon RX 6600 and RX 6600 XT has now surfaced. The RX 6600 series will be available in both mobile and desktop offerings and is expected to feature up to a 2,350 MHz boost clock, 8 GB GDDR6 VRAM, and PCIe Gen4 x8 connectivity. The PCIe Gen4 x8 limitation may be a deterrent for those looking to upgrade to Navi 23 on the desktop.
https://www.notebookcheck.net/AMD-Navi-23-Radeon-RX-6600-series-to-feature-8-GB-GDDR6-and-PCIe-Gen4-x8-for-both-desktop-and-mobile-variants-can-potentially-compete-with-the-RX-5700-series.539758.0.html