Normally you do something in response that would solve your perceived problem. In this case, it seems to be a random unrelated action they've taken to the problem they identified.
Sometimes some people change their mind.
Once you choose a license you just cannot get mad at people who read the license and then do what it says.
The cynical argument is that the spirit of the MIT license was kicking in, but most people would prefer for the spirit of the MIT license to not be like the way it is.
Here I think the Asahi Linux team came to some realization of this variety and made a change. I don't think there's much to argue over here.
They didn't even name the people in the announcement! This is fairly muted when it comes to re-licensing announcements.
Perhaps childish is right, but... hey, they are within their rights to re-license.