I've mentioned it, but I would actually prefer a remastered BK/BT to a Banjo-Threeie. I don't really trust Rare when it comes to the BK franchise, and there's less that can go wrong with a remaster than with a new game. You already have the perfect baseline for the remodeling of the characters and Spiral Mountain in Smash. You have plenty of examples of it working, from Crash N-Sane Trilogy, to what looks to be a great remastering of Battle for Bikini Bottom. Just looking at BFBB, while they changed up the physics engine to more closely match people's perception of how the old game felt like, outside of a graphical overhaul they kept everything pretty much the same. So we have the perfect template for one, and why not? Whereas with a Threeie, they would have to come up with new mechanics, characters, worlds, etc. There are many more points of failure. And by remastering the first two games, they would already have an engine to build a Threeie off of, if they choose to in the future, allowing for all three games to have a consistent graphical style. And that is the approach I believe the Crash series is taking.
They thought of remaking the first two games initially, but decided that with the amount of work that would require, they decided to just make a new game instead. And that ended up being Nuts & Bolts. So, with the precedence of what happened when they went with the more creative option, unlike what I would recommend usually, I'd recommend playing it safe, at first. Get that good will going, and if it turns out great and better than expected, they could then try the more riskier endeavor of creating a new game. But if I had to choose between one or the other, I'd choose a remastered Banjo-Rebootie for those reasons.