[shadowgovt]

Open collaborative editing is a useful feature enabled by wiki software, but I've never actually heard anyone claim it is core to the definition; it's more that it's the killer app enabled by the quick editing model embraced by WikiBase and the systems that ran on WikiBase after Cunningham made it available.

You can definitely have a wiki of one user. And it's extremely common for organizations to have a wiki of only authorized users. Although in a high trust circumstance, there's really a good reason to lock users who can read the wiki out from editing the wiki as long as edits are audited.

(Regardless of all of that, I'm fairly certain the deepwiki output is editable?)