While we take some time to wildly speculate about what could come of Isekai Musou, if anything, the other trademarks are Gakuen Musou—which would be academy-based to some degree if it’s actually the title of a game—Tensei Musou, Musou Play, and Musou Mode.
In the case of Koei Tecmo, the publisher behind the Dynasty Warriors/Musou franchise recently filed a handful of related trademarks in Japan, including one for Isekai Musou.