AES67 microphones exist. Shure, Audio-Technica, and Audix are just 3 manufacturers that make them. Some of them are called Dante mics and you have to turn on AES67 in a confirmation menu. I don't know that there are any good AES67 drivers in stock Debian or Raspbian, but a lot of AES67 devices can be used with any software that supports rtsp. Whether one install of rhasspy can handle multiple streams at once is a different question. Also, even the cheapest AES67 equipment is expensive enough that a new raspberry pi or odroid h2 per room would be cheaper.