Every update keeps valid the old themes. This means that a 2.0 theme will work in 2.2 and so on. I don't want to enable the old files because just one simple reason: That script versions are insecure.
Almost anybody here won't notice that because the releases looks pretty same but there are huge security improvements on each release and I don't feel comfortable with the fact that the main reason to ask for this files is theme or mod compatibility because people won't update their script just to keep working the theme or the mod. Old themes works in newer releases and the only difference is that this theme doesn't have the new features.
I don't want that you use older releases because there are secutiry risk doing that so you must understand that security is way more important than a theme.