That text snippet has been there since 2009 when the file was added to the kernel tree, unchanged, so I don't get what your point is? Nothing has been "switched" or changed, it rather looks like a case of "forgot to change the file to match current policy".
https://git.kernel.org/cgit/linux/kernel/git/stable/linux-st...
Btrfs wiki has the latest information and such the descriptions will be removed from the kernel source. FYI, please take a look at the following, recent patch.