Mr. Rubinson made a short comment about time in the WiSa thread that made me think, so sorry for the incoming rumbling. Keep in mind that all the following comes from someone who´s just a curious user who likes to listen to actual professionals; I lack the background on electronical engineering and software development. With that in mind, let´s go.
My experience with active speakers comes from listening to Genelec Ones and Kef LS50 Wireless II, which are meant for quite diferen aplications and employ quite different systems; I´ll focus on the Kef speakers for this. They have an rj45 jack; two in fact as one is used for wired internet connection and the other, to connect to the secondary speaker. Voodooless made the educated guess that chances are that the LS60, just like the 50, already use WiSa, so we can assume that the RJ45 jack is used to transfer digital audio.
So for a multichannel in a situation like this, would it be theoretically possible to connect several secondary speakers to a hub/switch via RJ45 cable allowing the content applied to the main speaker to "travel" to not just one but several speakers? This could allow to go beyond WiSa because with wired, it should be up to sofware development to handle the whole system.
If this is the case, the potential to add management for codecs (Dolby, DTS, Auro...) and eq (in house or licensed), would only be limited by the processor found on the main speaker. I have no idea if it´d be up to the task. Every speaker comes with a set of amps, a dsp instead of a crossover, a dac and a wireless module at least, with the master unit also including all the external connectors (RCA, HDMI, Coax...), so the potential to completely bypass an AVR or pre-amp is already there.
All in all, to expand the speakers beyond 2.2, it could be a matter of buying spare secondary units for the rear, sides, height and so on.
Let me say again that this comes from someone who teaches humanities for a living, so no idea if it´d be even possible or how hard it would be to turn Kef Connect into a "software AVR", so I migh be completely wrong.