Regarding: https://mms.mongodb.com/help/faq/backup/#how-do-i-perform-maintenance-on-a-replica-set-with-backup-enabled

The first bullet point regarding replica maintenance and backup states:

• Renaming or deleting a database by deleting the data files in the data directory. Use db.dropDatabase() from the mongo shell or an equivalent to remove databases.

Please rephrase to make clearer that:
1) Removing database files directly from the file system will require backup resync as this action is not replicated.
2) Running db.dropDatase() to remove database files is a replicated operation and therefore does not need a resync after.

The current phrasing lumps the action to avoid in with the best practice and can be misunderstood to mean db.dropDatabase() requires resync.