I do not know if a change to the default value of region-extract-function is supposed to be put in the NEWS; especially because it's a defvar, not a defcustom.

But that change broke my config because I was tweaking the value of region-extract-function.

Commit that changes the default value of region-extract-function: http://git.savannah.gnu.org/cgit/emacs.git/diff/lisp/simple.el?h=emacs-25&id=31f6e939334180add7bc11240343615a2e6350f6

Here is the associated change I needed in my config: https://github.com/kaushalmodi/.emacs.d/commit/ae38531ca5fb51d4b3303face4c5103ed4f70b3b

I need to update the region-extract-function because I want to add C-u functionality to C-w/M-w. (Please advise if there's a better way to do that.)