Too many people are confusing the two. Whenever lemmy.ml or its devs do something stupid, people go “Lemmy is getting worse and worse,” or “I’m leaving Lemmy,” or worse, “I’m leaving for Beehaw.”
If you’re using Beehaw, then you’re using Lemmy. Lemmy is the software these instances run on. If you don’t like lemmy.ml, join another instances that have rules that match your philosophy. Some instance hosts authoritarian or fascist shit? Turn to another Lemmy instance. Lemmy.ml is not even the biggest instance. People who just joined and are unfamiliar with the platform will just think the entire Lemmyverse is run by autocratic admins if we don’t get our terminology right.
I know what tankies are. I just haven’t encountered them much and haven’t seen them discussed much on lemmy.ml. They were a running joke in a certain part of reddit which is where I first heard of them. If by “there” you mean lemmygrad, then yeah, it wouldn’t surprise me, but if you’re over there at all, you’re sort of asking for it. I haven’t had occasion to look there much.