Beyond the economics, I wonder if implementation isn't the other issue.

Processors in the 861 $ range offer 16 to 32 channels, all of which are adjustable via RC. That simply doesn't work with M DSP's.

Sticking one 8000 at the end of one channel would defeat some of the benefits of Atmos and RC. If SpeakerLink provided different connectivity to each driver, then it would be a different story.

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).