After upgrading to Mojave, I checked around the settings for new features and saw that location-based apple ads (Security & Privacy -> Location Services -> System Services Details) was unticked (I'd unticked it some time ago in a previous version of the OS). Later I opened the new News app to see what it contained, and noticed that the welcome banner said it would use location based ads unless opted out, but I didn't think much of it since I'd already opted out.
Today I checked that setting again and noticed it had become ticked. After unticking it and opening Apple News, it doesn't seem to have been re-ticked again. Is this something it only does the first time News is opened, or have I misidentified the culprit?