that's the guidance I was remembering! Maggie, I've edited it slightly, could you add it to the Help pages for Trusted List & Duplicates (maybe edited more to fit context):
If you find that a profile for your ancestor already exists, request to join the Trusted List. Let the profile manager(s) know your relation in your request (for example, you might say "[This profile] is my great-grandfather, through his son John."). In very rare cases, you may want to create your new version of the profile and then later propose a merge if they're duplicates. This should not be done often. It's important that WikiTree only has one profile for every person. Duplicates damage our entire project.
Thanks for finding this Maryann!