To add some facts, I believe it’s an allusion to this:
Carthago delenda est - Wikipedia
So perhaps it could be characterized as a literary allusion rather than a willful use of a foreign language to communicate? There’s no bright line here, I’m guessing nobody would think Civis Romanus sum needs a translation, but this is more obscure.
But I think the ejection was principally based on it being a call to violence, and as for this -
I think this is a bit thin. It’s not simply a translation of the thread title, it is definitely “must be destroyed” rather than “must go”.
I would not be happy about “[public figure I like] must be destroyed”, and we should be consistent in our standards.