You can add more than one language. If you'd checked up on it, you would have seen that. I perceive this as complaining about advice without following it, and I find it annoying.
If you're still angry (and it sounds legitimate, especially if there was a subtle hint of a problem, but not enough to register fully), that explains where you're coming from, which puzzled me.
Aside: Unfortunately with webpages/webapps, they can and do get updated continuously, without explicit version changes or any notification at all. Ideally, all changes would be back-compatible, but then you end up with a mess (both in user interface and implementation). Continuous notifications amounts to spam, and is usually ignored (I do). Change is a problem. I'm not sure there's a solution.
I think back-compatibility is a deep, abiding, practical problem, in general.
EDIT "if the choices I made have been superseded and contradicted": just realized this is more than merely "backcompatibility of UI". In effect, they have destroyed your data. Although that sounds overdramatic, since the data itself is very minor (perhaps one bit, a binary checkbox), it's a clear trigger for notification. There might be some grey area for when your configuration is still there, but has a different meaning - but I think you're saying that your config is no longer there, and/or no longer has an effect.
I used to use Yahoo finance, and they had a nice display of 9 user-configured stocks at the top. In their latest redesign, this disappeared, and I couldn't find an option to bring it back. This was enough to make me spurn their product, and switch to google finance. It makes me think they have no idea what they are doing. I guess in this case, I had notification (as I could see it was gone). But if they had an explicit reference to it going away, even if it said "sorry, this is going away", I would feel better about it. And I have a sneaking suspicion that maybe it is still available somewhere, and I just couldn't find it.
So, changing the meaning of a user-specified configuration should probably trigger an explicit notification (and force the implementer to consider it); and deleting user-specified configuration should never happen, even if it has no effect. I think it should be treated as sacrosanct as other data stored (e.g. gmail emails, dropbox files etc). If changes render it ineffective, it should still be there, but with a notice: "this no longer works, use this instead". Again, this forces the implementer to thin about what they are doing.