We'll I don't have really a clue about copyright in such a case. But as I understood it, Masaya was only allowed to keep the websites and sell the healing CDs because Toshi had a contract with Healing World - and even now Toshi-Official website is gone anyway even though Masaya claimed that the contract is still valid for half a year. But basically that contract should apply to those works, Toshi and Masaya released under the Healing World label (besides it was Masaya who wrote and produced it, of course he is the owner of the copyright then)
If he would have rights for everying, I think that would have been a nightmare for X and the fans. And IMO that situation with Toshi alone was dangerous anyway.