Just updated to see it in action. Seems like a nice improvement for end users. Don't think there is any reason not to do this, other than a nostalgic desire for things to stay the same. Most sites already have a www. to . redirect in place and if you don't its a trivial change.
> Don't think there is any reason not to do this [...] Most sites already have a www. to . redirect in place
Most. Not all.
The browser is doing something out-of-spec for really no reason at all and it has the chance to break some sites.
www.domain.com and domain.com are never guaranteed to go to the same page. Yes, out of modern convention, they do now, but it's only a convention. Sites are free to break it, and some do, so to make this change is a bad idea.
The obvious difference is that that's higher up in the hierarchy rather than lower in it. www.example.com and example.com are controlled by the same entity; example.com and example.foo may well not be.
