The AMD Radeon RX 6800 XT and Radeon RX 6800 are now released. The RX 6900 XT will be released on December 8, 2020.
No surprise that NewEgg had nothing for sale at all suggests that inventory was very limited much like what happened with recent NVIDIA cards.
Most likely more video cards will be available into 2021. Manufacturing is slow at present due to supply chain problems.