Depends on the admin.
Arch servers are just fine. Just be sure to pay attention to Arch News to watch for manual interventions on certain updates. If anything, the older Debian packages can cause headaches occasionally. I personally use both distros as servers for different use cases.



You could make a document describing what each set of data is, if its useful to anyone but yourself, or if its safe to delete. You could offer suggestions of what to do with each set. I think of it as a treasure map that you leave behind. Maybe they will be interested in it, maybe they will pass it on to someone else.