Great find - it's good to know Ito was open to works like this at this time (and lends a bit more credence to the idea of a prototype machine). The Bandai connection here is interesting. Again, we've got a surprising amount of connections between the various people and companies at play.
Joe Blackwell, one of the lead developers of the machine (if the manual pic is to be believed), is now at Bandai Namco as their Customer Service Director. He's been there for years now and these games would have happened prior to his run, but its the same time frame as the machine, like you said.
Feels like there could be something going on with the Sega > Stern > Bandai Namco and some of their employees over the years.
Viewing post in I found two Uzumaki console games circa 2000
Also interesting that Joe Blackwell worked on a tournament system that seems to have been included in the Stern Playboy game (which is mentioned by gozooze99 in the original post)
This press release mentions the Sega connection as well: https://www.pinballnews.com/news/tops.html