As far as I can tell MADlib is not automl, it just provides various statistic analysis and "classical" ml algorithms as function/macros in various database, and integration seems to be quite different from the way we do it (and I'd say more complex for the user, but maybe that's just my bias talking).

So I don't think there's a lot of overlap there. But if you think otherwise and work on it or know someone that does, I'd be quite excited to have a chat, just to share experiences and tips if nothing else.