2.1.3 LiveCD /usr directory
in previous releases there was /uzip/usr.zip on the liveCD with empty /usr.
Now on 2.1.3 /uzip/ doesn't exist anymore and files are under /usr.
Is this a "permanent" change or only for 2.1.3 ?
Yes, it's permanent as far as I'm aware. It was done on purpose as a part of some recent work on the tools repository to streamline things and remove some external dependencies.
There shouldn't be any functional difference.