Put a validation rule on knowledge article. Example If status ~= Published and ISCHANGED(LAstmodifiedBy)
Validation error is not exactly what I was looking for. I was looking to lock the record as if it was going through an approval process. But it sparked an idea and I was able to find a solution to my issue.
I set up a process that would initiate an approval request on a KBA update. The approval would auto approve the request and lock the KBA.
Then by running an updating on 300 KBA's from the Salesforce data loader [all KB's that have a status of Published] it would trigger my process on each KBA, run the approval request, and lock that KBA.
It’s not the most direct way to achieve what I want but it worked, and I only need it to work once.