I've posted a bunch of this stuff on the KOS-MOS support thread a while ago, but I thought it'd be relevant right now since we're talking about these KOS-MOS "leaks". Even if all of them turn out to be fake, there's still quite a bit of stuff that I think could potentially help her:
• She is the face of one of Nintendo's first party studios, Monolith Soft, despite her being owned by Bandai Namco
• She made an special guest appearance in a Nintendo-made Xeno game as a blade alongside T-ELOS, a game that Sakurai himself praised
• Namco likes to insert her in a bunch of ****; they could possibly do the same with Smash
• Harada, General Brand Manager of Namco, has stated in the past that he would get Namco to make a Xenosaga HD Collection if there was enough fan demand for it. Smash could help with this
• Soraya Saga, the wife of Xeno-series creator Tetsuya Takahashi, announced back in October that she would be abstaining from retweeting Nintendo Directs in order "to avoid being involved in speculation" a couple weeks after Xenoblade Chronicles: DE was announced. She normally retweets these whenever something Monolith-related is to be shown (which could imply that she's trying to keep the surprise for more Monolith/Xeno-related announcements in the future, like maybe a potential Smash character). This could also just mean jack and she's just tired of people pestering her about the retweeting
• Companies haven't repeated yet for the Fighter's Pass. This could obviously change, but I don't think that's likely
• So far, none of our 3rd-party Mii Fighters have upgraded to playable status yet in this Fighter's Pass. The missing Namco Mii Fighters could possibly be hinting at a Namco inclusion, whether it be Fighter Pack #5 or post-pass. (I'm personally hoping that if Mii costumes do return with KOS-MOS, if she's Fighter Pack #5, Lloyd avoids getting costume'd and it's only the Gil and Heihachi costumes (sorry Tekken fans) that return with her)
• It is Monolith Soft's 20th anniversary. Xenoblade Chronicles has become a popular series for Nintendo in recent years. With Xeno this and Xeno that becoming more talked about, maybe Namco could want to capitalize on that popularity by advertising their own Xeno series in Smash
I suppose we'll have to wait and see if any of this **** means anything for her. Hopefully this week goes by quick (and hopefully a Game Awards Smash reveal actually happens).