To verify you have the correct version, look at the of the title screen or check the Software Information on your Switch Home Menu.

If you’re replaying BotW and found the original performance annoying, 1.6.0 is worth getting . It’s a “work” update – under-the-hood polish, not fireworks. For a first-time player, the original 1.5.0 is still fine. But for veterans, this makes Hyrule feel a little smoother without changing the magic.

The update did not change the game's core assets but instead: Split-Screen Rendering: