The trademark authority's website states the registration has been cancelled "because registrant did not file an acceptable declaration under Section 8".
Section 8 pertains to "maintaining and renewing an existing registration to ensure that the registration remains live". In essence, it is alleged that the trademark was not being used and, as a result of the inactivity, Sega has relinquished claim over it.
CVG has reached out to Sega, but at the time of writing it has no comment on the matter.
Shenmue 2 was released in 2001, and a new entry in the series has not been released since. However, Ryo Hazuki, protagonist of the series, has been featured as a guest character in numerous other games. Ryo was most recently added to the PC version of Sonic & All-Stars Racing Transformed.
In November 2013 an application for the Shenmue 3 trademark was filed to the Office of Harmonization for the Internal Market (OHIM). However, Sega later confirmed confirmed it as a fake and said it "is looking into the origins of this application".