Many, many production-grade devices (another example: the Behringer (Midas) X32) work right of the box. The fact that the iPad did not allow drivers forced almost all audio interface manufacturers to clean up their act and get fully compliant with the USB audio specification. The side effect of this is that they Just Work (TM) with Linux too.
(*) the one issue is that this particular device requires a specific version of the firmware to avoid a bug that only shows up on Linux. This is not true in general.