I’m not really interested in casting blame

A question about version numbers isn't really blame, though. Maybe it'll be better when Lemmy 1.0 is out and LW finally updates.

Is this because their Lemmy version is ancient and they refuse to update?

Must be cause if you downloaded something you’d be able to bypass their ads

They could also download the ads. People on an ad-supported subscription tier would probably expect that those are there.