Those still only work for text. What I'm trying to say is that it's possible Stallman was considering that "screenshot" means "dumping a graphics buffer to disk". In the case of text mode without the framebuffer, there is no graphics buffer to dump (at least, not one that's accessible on the computer), therefore the best you can do is dumping a text buffer instead.

You can of course synthesize a new image based on the contents of that text buffer (and that would almost certainly have been fine for the purposes of the question), but you can't dump a graphics buffer that doesn't exist.

He would absolutely have known about script(1).