With deregulated multichannels, there’s very little reason for the MDT service itself to exist.
The best outcome cost wise - both for the taxpayer and broadcasters - is for Ten to be a secondary service on the Seven or WIN multiplex.
WIN’s solus Riverland SA market multiplexes had changes similar to that - Nine (WIN) - #8516 by Shaun1997 - with the 7/10 channels now sharing a mux. I dunno if this was maintenance and was reverted or is permanant - but it cuts their transmission costs and given the regionals are already short on multichannels and it’s all MPEG-4, it doesn’t impact picture quality significantly to do so.