It was always a tankie den. The Lemmy developers are very openly tankies.
They held their heads relatively low during the whole Reddit exodus, but that’s about it.
Here are some examples: https://raddle.me/f/lobby/159606/is-lemmy-still-a-tankie-platform-or-are-there-actual
Did you update your filters?
I had the pop-up today, updated my filters then reloaded the page, and the warning was gone.