We have the same problem/wish. I tried writing an on save listener that finds absolute urls to the wiki and replaces them with internal links, but I could not find a safe way to get the name of the article from the url, because special characters can cause errors here.
I think you need to call the api to get the internal link/name, but I just could not figure out how to.
The “create an automatic redirect”-checkbox would be a solution, if the users would tick it - they just don’t.