I think that the pretty useless feature which helped systemd into Debian in the first place was discussed some time ago.
As you might know multi seat is supposed to make possible for multiple users to utilize a single desktop or laptop system in full blown GUI mode via special USB hubs, the main selling point of this curiosity was as a way to run schools in 3rd world countries.
However these extension hubs actually cost more than a Raspberry Pi, and the Pi has the extra selling point that the student can take it home and use it there.
I do not see any real need for silly things like multi seat and with every nanometer less and every new cell phone the price and power consumption per Ghz falls.
There is also the cloud and BIOD to consider, as well as laptops and tablets.
In my opinion 99+% of users really won't care about this curiosity, which is a cool concept with less and less actual relevance or practical purpose behind it with every passing day.
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Sent from my Android device with K-9 Mail. Please excuse my brevity.