One of the odd, but beneficial, things that Nintendo has done with the Nintendo Switch since its launch was bringing a bunch of games from the Wii U era to the current system. While this may not seem like a big deal, it should be remembered that though the Wii U had an impressive gaming lineup, it didn't have a lot of sales. And though some games did have millions in sales, they were small compared to what they would've done if the console had been more popular. Thus, the ports started coming. One of which was Hyrule Warriors Definitive Edition.
This port, in particular, was a bit interesting, as the original Hyrule Warriors was actually a million-seller on the Wii U. Which then led to an expanded port on the Nintendo 3DS (their handheld system) and then to another Dynasty Warriors spinoff via Fire Emblem Warriors, which released on the Switch and 3DS. Now, Hyrule Warriors Definitive Edition did bring some things to bear. Such as bringing in all the Legends content, as well as adding some new characters like Ravi from Legend of Zelda: A Link Between Worlds, as well as adding costumes based on the mega-hit Breath of the Wild.
The game itself released in May, and at present, it's not believed to have crossed 1 million units sold worldwide, which would mean that it did worse than the Wii U version. However, in a statement, Koei Tecmo (the publisher of the game), announced that they were boosting their performance expectations for the quarter because of sales of Hyrule Warriors. In their words, it did better in the West than they expected it to do. How much so they didn't say.
This piece of news is very interesting, for it could mean that it has now crossed 1 million units sold, which would make it another in a long line of ports that sold really well on Switch. Such as Mario Kart 8 Deluxe (which is actually the second-best selling game on Switch behind Super Mario Odyssey), Pokken Tournament, Donkey Kong Tropical Freeze (which did far better than its Wii U version), and more.
For those who have never played the game, Hyrule Warriors Definitive Edition takes the characters and world of Legend of Zelda and mixes it with the gameplay style of Dynasty Warriors. This game is a hack-n-slash title in the 3rd person, where you fight armies of enemies in order to complete certain objectives. Hyrule Warriors took this a step farther by letting characters pick their own weapons (after earning them), and bringing in characters from different Legend of Zelda timelines in order to create a bigger party. Characters like Darunia, Midna, Fi, Zant, Ghirahim, Ganon, and more all appeared, and more were added later as DLC, which was all compiled for the Definitive Edition.
Given the success of the versions of Hyrule Warriors and the success of Fire Emblem Warriors, it goes to reason that Nintendo could dip their toes into the well again should they feel they could have success once again.