Access Request Settings Part 1

Office 365 SharePoint Online already has good adoption, but all of the features are still new to many people.  Here’s my question that the great and powerful internet can’t quite answer yet:

If a Site Members Group has the Contribute permission level (& not the Edit permission level), does this trigger the “Members cannot share this site because this site is missing a default members group.” error in Access Requests Settings?  I don’t think so, but it’s the best place I have to start at the moment…

I don’t see this listed in the updated Microsoft page on “Understanding permissions levels” (link).

On Timmy’s Blog (Link) the author’s asking the same question, but no one’s answered him yet.

A more specific search for [Members cannot share default group site:microsoft.com] turns up no other results…

Could there be a distant relation to this kb article http://support.microsoft.com/kb/2911390/EN-US?

Is there something else I’m missing altogether?

These are the steps I submitted to Microsoft Support if you want to try and answer it yourself:

1. Go to Office 365 SharePoint admin center.
2. Create Site Collection with default Members Group with the Contribute permission level.
3. Check checkbox for Site Collection.
4. Click “Sharing” button in SharePoint admin center Ribbon.
5. Check “Allow external users who accept sharing invitations and sign in as authenticated users”.
6. Return to Site Collection.
7. Click “Access Request Settings” in Ribbon.
8. Check “Allow members to share the site and individual files and folders. “
9. See error in red text: “Members cannot share this site because this site is missing a default members group”