I suppose M could follow the ADA/Trinnov model, where there is a tack on integrated box that does the room correction and leaves the processor to only decode. They would need to break from their external HDMI policy and have a processor that does full Atmos.
ADA

They could do their own, with an MMHR connection.

Primary: MD600, MS200 (SpeakerLink to AES), Trinnov ST-2, Ayre V6-xe, Salk SS8 3x LRC.
Secondary: MC600 (whole house).
Zone one: 568.2, G57, MS200, Spatial Hologram M2SE.
Zone 2-6 (Awaiting assignment).