More specifically: news are checked in between repo.postsync.d/ and postsync.d/ So if you pull the news manually into your tree in postsync.d/ hooks, this will sort of mess up expected behavior. This is creating minor annoyance for our postsync.d hooks https://github.com/hasufell/portage-gentoo-git-config/pull/6 which help to run the gentoo tree directly from git.
There's a patch in the following branch: https://github.com/zmedico/portage/tree/bug_558322 I've posted it for review here: https://archives.gentoo.org/gentoo-portage-dev/message/6f0d6cb3af6bccaaeeee137822f7297d
This is in the master branch now: https://gitweb.gentoo.org/proj/portage.git/commit/?id=bafb62bb32432094f1c413a9a7e2dc902ff11a5a
/etc/portage/repo.postsync.d/example
correction: Released in portage-2.2.21