Changing an Office 365 group from Private to Public; from the Office 365 group admin itself VS from the sharepoint permsion setting popup

In Office 365 groups we have 2 approaches (at-least 2 approaches) to change the group from private to public OR from public to private:

  1. From SharePoint site >> site permission, as follow:-

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  1. From office 365 group admin, as follow:-

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now i have noted in the first approach if we change the Group from Private to Public, the SharePoint will add “Everyone except external” inside the SharePoint members group, while using the second approach this will not happen.. so is my assumption correct? and why we get this behavior, although we should be doing the same thing at the end…