I'm pretty sure they still give lead time warnings, at least they did in the 90's. Gundam X was a good example of "oh crap, budget's been cut, we better tie this up fast." Only show I can think of, at least that's been brought over here, was Candidate for Goddess, which literally just abrubtly ended. Big O I don't consider falling under this catagory, since I don't believe it was ever intended to have a finite ending. Then when they tried, they made it worse than the original ending...