For the record, that trademark issue is only with regard to merchandise, to be specific "T-shirts; Shirts; Sweatshirts; Jackets; Headwear."
The Dream Theater trademark for "entertainment, namely, live performances by a musical band" is still active. Maybe the merchandise also includes the Ytse Jam releases, but I doubt it's an issue with MP trying to keep the band name, as some seem to be insinuating.