The first Radeon RX 6900 XT from a board partner is here and is by ASRock. The card is merely a reference AMD design by another name though, with no ASRock branding or customisations to speak of. Custom RX 6900 XT cards should arrive after December 8, if there are any.
https://www.notebookcheck.net/ASRock-unveils-the-first-Radeon-RX-6900-XT-by-a-board-partner.506093.0.html