I changed the original link. Does it work now?
To get to the actual filing page, you have to click the link under 'その他 '
It works now, thank you, it's very interesting.
It seems the potential uses for her are related to technology and games. Mobile games, video games, toys, amusement parts (maybe Namco Namja Town?), slot machines, musical performances...
【公開日】平成30年5月22日(2018.5.22)
[Day available to the public] 5-22-18
【公報種別】公開商標公報
[(Trademark) bulletin classification] Open to the public trademark bulletin
【出願日】平成30年4月27日(2018.4.27)
[Application day] 4-27-18
【商標】
[Trademark]
So I guess them releasing her out of the blue wasn't that out of the blue. I don't know how trademark stuff works, but this sounds like the classification is for public use, is there a private use equivalent (if they had used her within the company before)? They filed for public trademark April 27th Japan time, got approved on May 22nd Japan time, then released her Vocaloid on the 23rd (our time) which I think is the 24th Japan time (due to timestamps on news articles about her in Japanese). Thanks for sharing your find.
Edit: What I don't understand is why is this only 1 page (starting with item number 9).