How could she know anything about Monolith Soft's new project if it's not from a more internal source ?
Unless Xenoblade 3 will be announced at the Jan. 12th event.
She knows very little, and given her inability to not leak everything I don't think she knows more than its mere existence. Marketing would be able to tell you that much.
Notice the difference in what she's reported *in detail* on anything from Ubisoft vs... just about anything else. The only major info she's shown on Nintendo stuff is the ports information for MK and that could well and fine be from an external porting studio or marketing as I expect that title to well and surely be in the presentation.
Since Bamco is likely working on Smash, most of that is also likely out of the eyes and ears of marketing until closer to release and as such, again, we see very little of it and only hear vague rumors on the wind.
In fact, I'd say that people who know more about Nintendo internal works (probably Emily, since her contacts are considerably deeper from what I can tell) has remained silent after the initial flurry of leaks/info on the Switch. The more you move away from marketing and get into more core projects, the closer you get to really pissing people off and potentially getting major developers in trouble, and so this is usually where leaks cut off because of mutual respect between leakers and their informants. Marketing is considerably harder to control in this fashion as that information is MUCH more wide spread.