My opinion is in favor of realistic shadows, despite this not being a realistic game.
It's not just because blob shadows were technical limitations at the time and realistic shadows would look better in this beautiful game. (Though those are also valid reasons.) Blob shadows are training wheels. At the time of Banjo-Kazooie, 3D platform games, or 3D games of any kind for that matter, were still a new thing for most people. Even the first level was absolutely minuscule, compared to any of the others. It was a new genre and a new dimension.
Today, this is unneeded. We don't need training wheels anymore. I don't have trouble blasting around at high speeds from platform to platform in a Sonic game, nor do I have any trouble landing jumps correctly in a Mario game. Besides, while people often clarify Banjo-Kazooie as a platform game, that was never particularity accurate. Seriously, how often did you actually have to jump on things in that game? (ESPECIALLY with accuracy?) There was mostly just running. And it looks like that will be very much the same here.
We don't need pinpoint blob shadows in a game about running around vast, open spaces.
The only way I can see something like blob shadows actually being necessary at this point is if the game has multiple difficulties, and blob shadows are used in the easy skill level(s).