I don't know why Tubi only streams the first 52 episodes of Duel Masters. I went through Hasbro Studios' old sites and I couldn't even find a listing for the original show. They obviously retain the rights to it since they've uploaded clips of it to their YouTube channels. I don't think they dubbed more than those 65 episodes. If they did, they probably would've dumped them onto Monkey Bar TV, which was Hasbro's short-lived streaming portal.
Odds are good Sacred Lands was produced in Japanese. These all come from different production houses, but both Transformers Armada and Zoids Fuzors debuted in English before their Japanese launch. It's highly likely there's a Japanese version of GI Joe: Sigma 6, as well. The dub's credits list a Japanese recording studio, but 4Kids did the show's music in-house. These are all properties Hasbro had a hand in throughout the early/mid-'00s.
(Several years later, Beyblade would get three spinoffs made for the western market. They were all produced in Japanese, but only one saw release in Japan. The Japanese versions of the other two very quietly surfaced on a Chinese streaming site. Just mentioning it as another example of a Hasbro-linked anime property that did something similar.)
GI Joe: Sigma 6 being originally recorded in Japanese makes a lot of sense, to the point that I refuse to consider any entries on an iceberg I'm working on alongside cTgman. It's possible that it's probably locked somewhere within the vaults of GONZO.