I’m not absolutely sure but I think when I started on Medium they did call comments “stories”. I recall my consternation back then when I wanted to download all my “stories” and that included all my comments so the file was useless to me. You could also select to have your comment show up on your profile page or not as you made it. Now they have tabs and responses has its own but not sure when that happened. Anyway, think that’s what happened so its legacy language in that email.

And wow, I should be commenting more! I’ve never risked breaking that limit.