It fully supersedes and replaces the official public one, after integrating it, WU doesn't re-download the public one.
I know but my question was that if I apply this update, will I still get public cumulative updates via WU? But the answer is yes
That's not because WU recognize it rather because it's flagged as superseded by CBS stack, since all cumulative updates now shares the same CBS package name: Package_for_RollupFix
ofcourse....i dont see why not. this update is no big deal if it was the public would have pick it up.