Could this be the new SRAM Red XPLR AXS? What caught my eye was the beefy SRAM transmission-style rear derailleur. Launched as part of its Eagle mountain bike line in 2023, the SRAM Transmission ...
It gets even more interesting, as SRAM also has Apex Eagle AXS. This works with an Eagle 12-speed cassette and really wide-range cassettes with 10-50T or 10-52T gearing.