I just downloaded canary and tried it and you are absolutely right.

about.www.github.io shows as about.github.io

I'm on board with this change in general, but this is absolutely something that needs to be fixed.

Not only is that just annoying and wrong, but it could be dangerous in some situations.

Also, it doesn't just stop at one removal.

    http://www.www.about.www.www.stuff.www.www.example.com

shows as

    about.stuff.example.com

Interestingly though it doesn't remove it if it's the TLD, or the actual domain (so stuff.www.whatever shows as stuff.www.whatever).