@Stephen Rice,@Rafael Lopez-Uricoechea, got another problem. We use this new sharing experience for OneDrive and the SharePoint site documents that is a part of an Office 365 Group. They work. However, we just found out that this new sharing experience doesn't apply to the SharePoint site that is created directly within SharePoint Admin Center. Let me call it "the classic SharePoint site" to be differentiated from the SharePoint site of an Office 365 Group. When I was trying to share a folder/file by entering the recipient's email address, I got an error "Your organization's policies doesn't allow you to share with these users. Please contact your IT department for help.". And there isn't such a new experience of "Only the people you specify will have the access to edit" in such a "classic SharePoint site" anyway. Why is that? Did I miss something?
Thanks,
Dean