some of the series (mostly in the beginning) is not in Chono order. they dont do that as often now.
This is wrong.
As for Onaconda. You must have mixed up the order you watched the shows. Because his final appearance in SW: TCW was when he died.
Edit: I see... I was mistaken. But Wookieepedia isn't counting that season 3 episode as canon or they haven't updated... this is strange.