Nintendo has been speculated to be planning a new Direct broadcast in the coming weeks that will presumably reveal Breath of the Wild 2 among others. The official announcement is still pending but the rumor mill has already started churning breadcrumbs for the community to follow.
While streaming a couple of days back, well-known Valve leaker Tyler McVicker slipped some small details (via Reddit) for the upcoming sequel. Unlike the original, Breath of the Wild 2 will be completely linear at the start and Link will not be climbing any towers since he has already explored Hyrule in the timeline.
Secondly, the world will be covered with a miasmic version of Ganon. Link will need to clear each location of the infection before moving any further, which also means that the world of Breath of the Wild 2 will be mostly locked down and without the freedom to move around Hyrule at will. However, the locations will be much deeper than the original. McVicker hinted that dungeons in the sequel will be strongly inspired by a game known for spreading dungeons in an open-world setting — leaving it on the community to find out which game exactly.
Nintendo took a lot of inspiration from two games when designing the world of Breath of the Wild 2. One of them was Red Dead Redemption 2 from Rockstar Games, which has been public knowledge since last year. The second one remains unknown for the time being and may possibly be the one that McVicker hinted to be involved in the dungeon-creation of the sequel.
For the record, McVicker has had an accurate past when it comes to leaking Valve-related projects. He leaked Half-Life: Alyx nearly half a year before rumors began popping up about something Half-Life in the works at Valve.
Breath of the Wild 2 is under development out of necessity. Nintendo previously confirmed that the developer had just too many ideas to work with on the original. At the end, it was deemed better to explore some of those ideas in a sequel rather than tuck them away on a shelf. As such, Nintendo is looking to offer new playable experiences with Breath of the Wild 2 that exceed those of the previous — first — installment.