Shigeru Miyamoto has revealed that the Star Fox 64 Remake and Yoshi and the Mysterious Book happened because of the characters' appearances in The Super Mario Galaxy Movie.
Star Fox has had a bit of a whirlwind year. From being considered one of Nintendo's "dead" franchises after the monumental flop of Star Fox Zero on the Wii U, it's come back in a major way in just a few months. Fox McCloud played by Glenn Powell was announced for The Super Mario Galaxy Movie right before it was released, less than a month later a new (well, old) game was announced, and the following month it was released as a Nintendo Switch 2 exclusive. But according to Mario creator Shigeru Miyamoto, that was no mere coincidence.
Speaking to Famitsu (via Nintendo Everything), Miyamoto explains, "I don’t decide everything about the lineup, but we did discuss that ‘we have an idea to include Fox in the script for the [Super Mario Galaxy] Movie, so we definitely want a new Star Fox game.'" But Fox wasn't the only character to benefit from their starring role in the film, as Miyamoto explains, "It was decided early on that Yoshi would appear in The Super Mario Galaxy Movie, so we decided to make a Yoshi game, and that’s how development of Yoshi and the Mysterious Book began."
Synergy between the games and the movies goes both ways too, as he explains that while working on The Super Mario Bros. Movie, Nintendo was also developing Princess Peach Showtime, "and we talked about things like, 'If we have this game, shouldn’t Peach be more energetic in the movie too?'"
Miyamoto explains, "It’s a case-by-case situation, but I think we’ll continue to maintain a good relationship between games and other developments."
Obviously, this strategy does make sense and has been a thing since the beginning of movie games.
You could even speculate Super Mario Bros. Wonder to be a part of this based on the proximity of its release to the first film, but Miyamoto didn't mention if that was the case. However, the Donkey Kong design that would be brought forward into the Switch 2 era was debuted in the movie, so I'd expect to see synergy between games and movies being a big deal for Nintendo going forward… especially with The Legend of Zelda: Ocarina of Time remake coming this year ahead of the movie next year.