See the relevant legislation here - https://www.legislation.gov.au/Details/C2021C00389/Html/Volume_1#_Toc83810378
There’s a specific definition of a trigger event for the increased local content requirements, which the acquisition of Prime meets, as it’s fairly specifically crafted to basically be an “if the metros buy the regionals” clause, so we are very unlikely to be in a situation like the joint venture station situation with whether the local content rules trigger event applies.
The law from my reading passed as proposed in the summary table above from Nick. There’s a 6 month period before the new requirements actually take effect.
Some exceptions are that this trigger event doesn’t flow on to Ten West/MDT - section 38A/38B licenses are specifically excluded, there’s also about 3 pages of legislation to explain that GWN doesn’t have to service all 4 of their legacy call sign areas separately - with the points total counting as the whole regional WA market.
So I suppose good news for Mildura, as Prime should be required to at least have dedicated local news, though obviously GWN already far exceeds their requirement.