In the classic division, "teaching" consists in giving undergraduate classes, and "research" consists in the whole spectrum between working all on your own and managing a PhD factory (3+ students a year).

So this article is really not saying anything controversial in the strictly ontological side of things, in fact it's already a relatively common stance to prefer supervising few (or, more rarely, none at all) students.

This researcher is saying "when I consider hiring someone as a workhorse, I might prefer AI instead"; what's the harm in that? Too many PhD students are used as disposable cheap labor, seeing little personal growth in their PhD journey and being generally neglected and abused.