As tweeted by @momomo_us; it appears that ASRock has teased a brand new RX 6900XT model in Asia called the Formula OCF 16G. We don't know much, but we can assume it comes with 16GB of GDDR6. Presumably this will be ASRock's flagship model of the RX 6900 XT, built specifically for overclocking.
If you are unfamiliar with the "Formula" branding, it's something ASRock came up with years ago for its motherboard lineup. These boards were targeted specifically towards overclockers, with excellent power delivery systems, and extra features targeted towards bringing users the best overclocking experience possible from the company.
From what we can see, the RX 6900 XT Formula OCF 16G is a beefy triple slot card with a triple-fan cooler and a heatsink that covers the full length of the card. Aesthetically the card is rather neutral in color, with a grey and black theme, but there are yellow accents on the side of the card, showing off this is a Formula product. The only RGB we can see is a small light bar on the side of the card, right next to the Radeon branding.
Looking at the PCB, we can see what seems to be a BIOS switch, so hopefully, this means the Formula will be packing multiple BIOS. We will probably see one BIOS optimized for quiet operation and the other for pure performance, like other dual BIOS graphics cards.
Unfortunately, we don't know actual specs for clock speed and things such as power delivery. So hopefully ASRock will release more info on this card soon. But like all graphics cards currently, good luck trying to purchase one of these cards at all.