The Behringer X32 is a rare product that is designed well and built well. The digital aspect, the analog aspect, the user interface (hardware and software), the layout, the speed, the remote control feature, all work very well together. By using it I got the impression that it's built by hackers. It's good to know it's powered by Linux.
Where did you get the idea that it's powered by Linux from?
I'm not sure what the OS on the X32 (or the Midas M32 sister model for that matter) is from factory.
The higher end Midas Pro consoles do definitely run on Linux though.
The partition table listing from the microSD card shown in the video (before installing a custom u-boot/Linux) shows partitions marked as the Linux partition type at least.
That's not saying much. Partition type names are a hot mess.