But they had superman returns/smallville concurrently. But i suppose you could argue he wasn't really superman.
DC is kinda bi-polar about it too. Sometimes they relax it or allow it to be ignored, and other times they hold firm to the idiotic idea that it would "confuse audiences," like people couldn't tell that the Batman rogues gallery appearing in the Justice League cartoon was different from the movie characters. Plus they allowed part of that rule to be ignored by including Joker in a number of episodes.