Universal URL's to files in OneDrive for Business
As in other sync services like OneDrive personal, each file needs to have a unique URL regardless of if that file is moved to another location within OneDrive for Business. That way, when sharing links in programs like OneNote, the file can be rearranged and organized as a project grows, but the links will still always point to the unique file URL.
And simply replace the UPN in the OneDrive URL to an ID, that would not be changed, if you change the users UPN. So you will have less death links.
Yes and for some situation it's really bad, that links change is a username is changes or files are moved to a group or other sharepoint location within the same tenant.