I don't think this could work. Private companies like Twitter can enforce limitations on content that the a government run platform couldn't enforce due to the first amendment.
If it federated with Mastadon (or was a Mastadon instance) then others could seamlessly pull those official comms into their feed without having to ever navigate to the platform. Or, for those of us that don't care to have a centralized feed, we could just go to the instance directly for government comms. No more of this "get nagged by twitter ads while I try to read updates from my local government".
The main difference I see though is that since Mastodon provides RSS feeds, I could at least follow the feed of my country's emergency services without needing a specialised app.
This was especially useful for things like transit, or emergency situations. If there was a snowstorm, I would check the BC transit Twitter account. When there was an active shooter at my university, I checked the Ottawa RCMP Twitter account.
And I relayed that information to others, including people like you, making sure that even if you don't have Twitter you had the latest information. Now, Twitter can't be relied on for the latest information anymore. Government websites are not real time. There were millions of people using Twitter for this, and now they're no longer going to use the platform. This is absolutely a loss for the platform, no two ways about it.
There are no 1st Amendment issues with Amber Alerts or weather alerts pushed to my phone, for example. But if CNN or Fox News are allowed to post to this proposed service, now we've got a different animal.
That said they just outsourced that shit to a chain of large corporations, all who have lost their contracts for doing really dumb and bad stuff, and they've definitely dropped the ball really hard on emergency warning alert systems working properly before. People could have died in their sleep. [1][2]
[1] https://www.theglobeandmail.com/news/british-columbia/bc-cha...
[2] https://www.vicnews.com/news/new-national-emergency-alert-sy...
Some content about manitoba seems like a small price to pay for accurate wildfile info.
Plus I don't see where members of the public can post content on PBS for the first amendment to even come into the picture. If an employee posts something objectionable, they can be fired regardless of the first amendment, just like any government employee.
