I think you're correct, but the announcement is still welcome. People are gonna be waiting forever for any semblance of federal guidance, so at least these 3 states has decided they'll make calls together.
The US governmental system has a long history of injecting bureaucratic nonsense that takes on a life of its own and ends up with outcomes like "teaching to the test" instead of being a net benefit.
I would feel differently if this were an announcement of a joint task force for sharing data to help each state make the best decisions possible. But this sounds to me like it will just make it harder for each state to make a decision on their own and that it probably doesn't really add any value. And that concerns me.
I have the same beef with Mayor Breed in San Francisco, who has otherwise shown standout leadership. She's publicly worried that people will let their guard done by assuming things are under control. Rather than worry about people's feelings and opinions, she should be setting expectations exactly as I described above.