Nintendo is likely to be observing other open world action games like BotW. As for which games Nintendo is looking at, there are a few well-known titles that could give the company some ideas in keeping the Legend of Zelda formula fresh.
On the flip side, Nintendo is looking to other big open world games for some inspiration in building Breath of the Wild 2. After the enormous critical and commercial success of The Legend of Zelda Breath of the Wild, one would think that game developers everywhere would be doing all that they can to emulate what made the game resonate with so many people.