Makes sense.
For a reference point: I'm a millennial, living in a pretty liberal state of the US. Reading the front page of Reddit (not logged in, running ad-blockers so I think I get a "generic" experience), Ars Technica, occasional HackerNews threads, Something Awful forums. My friend circles are unanimous that Israel is an apartheid state, Russia is an invader, immigrants are not any kind of problem. It includes a few trans people who are vocal about their experiences. I would not call it a radically progressive group. For example, I don't think most of them would actually be comfortable with mass-executions of wealthy people.
Before joining Lemmy, I'd never encountered "tankies" in enough quantity for them to have any kind of label or for anyone to self-identify as "anti-tankie". It's still a weird idea to me.
They said "please stop donating". Returning funds or organizing what to do with them is a bunch of work. If they're shutting down because running the instance is too much work and they feel hassled then I wouldn't begrudge them just keeping the few thousand left over.