I'd say that it's more to do with SE holding their cards closer to their chests. There was nothing to suggest Sage at all so anyone correctly guessing that would need insider info or a lucky guess. All the speculation videos I saw were based on decent logic which is the best you can ask.

Plus the purpose of these speculation videos isn't really to provide accurate news info (that comes AFTER the announcements) but to stir the discussion among the community, which they do. People want to talk about it and hear others opinions, so it makes sense that content creators put theirs out there.