Not very useful, surely (now that we have hex escapes).
[I'd still retain \0 as a special case, since it really is useful.] But a lot more useful than a hundred backreferences.

And I'm as a matter of principle opposed to changing something that's been in the language for decades for the benefit of someone that's by their own words "just learned Python". [Changing documentation is fine.] They by definition don't see the whole picture. Now that we don't have a BDFL anymore, I think it's vitally important to have some principles such as this one.