I have an Addin that is used across the organization (50+ people). I used the shared folder because:
Designating a well-known folder on a network drive is a convenient way for many people in a workplace to use the same add-ins.
However, if one person decides to delete the Addin from their Pro using the 'Delete this Add-in' button, it deletes the the underlying .esriAddinx file, as indicated in the Managing Add-ins documentation.
If you use the Add-In Manager to delete an add-in that is loaded from a well-known folder on a network drive, the .esriAddInX file is permanently deleted, just as it would be if you used Windows Explorer to delete the file from its location on disk.
There is nothing stopping curious users from deleting the esriAddinx file. This is a huge problem because the Addin is now broken for everyone else and for future users until the esriAddinx file is restored. The 'Delete this Add-in' should just remove it from the users Pro addin list and not delete the underlying .esriAddinx file.