Hayato also has a login screen as well. Not sure about the others. Interesting that they added the Sengoku forces into the alliance against the BM. It might just be promo material another version of MS created for the new upcoming 5th job skills for the non-KMS classes.
If anything, it will just be an extension of the non-KMS class storyline. So basically the story that happens after the events of Monad. In relation to the mainstream story, it will likely be post-BM.
Chronology wise, it probably looks like this.
Captain Vaga (RIP) -> Class Storylines -> Masteria = Zipangu -> Stellar Detectives -> Monad