By definition, in that limit they'll be genuinely adding to the discourse so presumably they should stay.
Edit: More correctly, they'll be making contributions to the discourse that closely mimic the human distribution, so from a pure content perspective they won't be making the discourse any worse in the very short term.
Edit: More correctly, they'll be making contributions to the discourse that closely mimic the human distribution, so from a pure content perspective they won't be making the discourse any worse in the very short term.