I guess, but i think it would be a hard problem to determine when a misspelling is close enough we should auto redirect without telling the user, and when its unclear enough that auto redirecting is too much and we should only have a little "did you mean x" prompt like we currently do.
With respect to this point, I think the author is saying that it's a dated system that introduces a ton of potentially unnecessary link rot. Basically, there's a ton of unnecessary technical debt because there isn't a more automatic way to set up/maintain redirects and instead often multiple manual entries are added for e.g. common misspellings of article names.