After the success of Breath of the Wild, they're obviously hoping for an equal success with a sequel.
The thing about sequels is they are hit and miss - sometimes they're as good as the original, sometimes they're better, sometimes they're not as good.
It looks like it'll be the same map, though obviously there will be differences here and there. It also looks as though Ganon is getting resurrected in his mummified body from Twilight Princess. (for the other timelines, we'll say either they end at Breath of the Wild, or Ganondorf died and reincarnated a second time with a body intact between Legend of Zelda/Wind Waker and Breath of the Wild)
This whole thing opens up possibilities for improvements in a few common complaints about the game.
First, there could be more Zelda-like dungeons than the Divine Beasts. Maybe more variety in bosses too. (as long as they can be Flurry Rushed...) That was a common complaint.
Second, if Ganon is becoming Ganondorf again, he could have lines this time, maybe some more screentime. (think King Sombra, if you're familiar with that show, he dies once with very little screentime and lines, gets resurrected with more lines and screentime and mostly stays in physical form, to be killed again of course. Like Malanya "Do you plan to revive it just to kill it again?" Sombra's a unicorn too which is close to a horse)
Though, I've also heard complaints that the game is too easy. I think it's moderately challenging, not too hard that it's annoying, while not too easy that it's boring. I really hope they don't up the difficulty here.
Also, I'm curious as to what the health/stamina system is going to be. Are the shrines going to stay? With the same challenges or different ones? What about the towers? I assume there will still be Korok Seeds, breakable weapons, etc. Also, will there still be Guardians walking around for Ganondorf? Will he be fought at Hyrule Castle or set up his own castle somewhere this time?
Of course, once the sequel's out, no one's gonna remember the original I bet, or play it again. Unless it disappoints.
Another thing I'm concerned about is, anyone who has Breath of the Wild on Switch, will the sequel fit in its memory? (won't be an issue for me coz I have Breath of the Wild on Wii U, and only games I have on Switch so far are Super Smash Bros. Ultimate and Super Mario Party)