MK8 rapidly approaching Pokemon Sword and Shield, SSBU will be a bit more difficult.

No game has been longer in the top 30 than BotW.

Which is all the more impressive for the fact that Zelda as a series hasn't been super popular in Japan. BOTW was truly a breakthrough title in more ways than one.

When you back to the roots and adding features for the most popular games, like Minecraft, Skyrim, Witcher 3 and cut the bloated features dominant in the other Open world games and focus on exploration ( Zelda roots again), you may have a good product with worldwide appeal. 

Can Switch do a third full sweep this year?

Not necessarily as BOTW's appeal is due to exploration but not the type you're mentioning here it's the ability for the player to actually play the game in ways they want to experience it that drives the appeal. Many games say play how you want but you play as you want with in the same set framework of the game's experience for example you may choose a different dialogue option or you may just opt for stealth instead blasting through, in BOTW the experience is quite formless as some people play it like an adventure game while others have approached the game like an action game similar to DMC while someone else will play it like a sandbox.

To put it simply BOTW has many of the features like the other open world game but it's different execution leaves it down to the player to explore what they want to utilize for their own personal experience that's why it has higher appeal tbh.

Ghost of tsushima released this week. so no 3rd full sweep this week.

Great BotW-inspired game. Better than Genshin

Doesn't Sony import the console to China yet or why do people import their consoles from foreign countries in China?

Any chance of Switch having a third party top 5 the coming weeks?