As far as I know, Xaero’s or any other minimap mod doesn’t really have a global waypoint sharing system for servers (you can at least use the share button in Xaero’s, but this is by no means automatic and uses a chat message). Making a plugin communicate with a mod sounds like hell.
The most i could see realistically happening in the future would be something like Dynmap + possibly placing markers on it for public warps. It would have to be a plugin only solution anyways.