Step 3 of https://api.drupal.org/api/drupal/core!UPGRADE.txt/8 says
Also remove all of the files in the top-level directory, except any that you added manually.
it doesn't exclude or include hidden files explicitly, so my logic would say 'all' includes hidden files.
later it says
cp -R drupal-x.y.z/* drupal-x.y.z/.htaccess /path/to/your/installation
which does not copy any hidden files except
This would suggest not to delete the old hidden top level files. On the other hand the new version/patch of Drupal 8.y.z comes with (new?) hidden files.
So my question is: what is the correct way to handle top level hidden files other than
.htaccess while upgrading Drupal 8?