What about Bethesda? Pre-FP5 some of your sources were saying them, no?
A couple of things that shaped their predictions:
-Long standing rumor that there were going to be two Western characters after Banjo. (Master Chief didn't start being taken seriously as a real possibility until late December.)
-Nobody knew yet that it was completely possible for big companies to have Mii costumes without playable characters (Ubisoft). Like I said in December, most of my contacts believe Cacomallow is real so assuming Cacodemon was attached to a Bethesda character was just a logical conclusion at the time.
-Very prevalent belief that the Fighter's Pass was going to be entirely third party, further supported by the fact that first party characters almost never came up.
-Very prevalent belief that the Fighter's Pass was predominantly going to involve companies that supported Switch right off the bat (Dragon Quest XI and Skyrim were pretty much the first third party games announced back when it was simply NX).
-Very prevalent belief that the Fighter's Pass wasn't going to have promotional Nintendo characters ala Corrin.
In short, predicting 5 was a mess because there were factors that people didn't know were relevant, people really weren't sharing information, leads were few and far between, everyone was kind of tired and pissy anyways, etc. That whole two month period was, objectively speaking, total dog**** and I'm glad it'll probably never be that bad again.