Actually, I think the old references are relevant. Sometimes those bug fixes and workarounds no longer matter. Windows 95 and Internet Explorer are long gone, we don’t need to architect our code base any longer to support them, but everyone’s petrified to remove the support for them.
Or in the language of fences, the fence might’ve been built for a herd of cattle that no longer exists. Raze away!
Right. Chesterton's fence isn't "never remove a fence". It's "understand why it's there before you remove it". If you look and find out it's for a long-unsupported platform, go for it.
In practice, a mature codebase is likely to have a mix of now-useless warts and seemingly useless but actually essential elements, along with some that fall in the middle (most often, in my experience: attempts to fix valid issues but in a way that no longer makes sense).