Original creator was only involved in the "first season", all the way back in 2000. Two new seasons were made in the 2010s when adult swim decided they needed to "bring it back" with a completely new director and animation studio. It wasn't good, and now they're committing to two more new seasons.

Most of us agree that all the follow up seasons are non-cannon and a mess. It distracts from what a good series the original 6-episode OVA was.