When it comes to a classic franchise like this, there is no room for mistakes. A bad release can cost Nintendo a lot more than lost profits in the immediate term, and the studio should be very careful with how they handle every step of the production.
They are likely well aware of that too, which is why they have been trading so lightly with their communication with fans. The studio knows how to handle this aspect of a game’s release as best as possible, and they still have a lot of time until 2017 to release even more marketing materials too.
It will be an interesting release for sure, especially for those curious to see how Link has changed since his last iteration. There are rumors that the character might find himself affected by the time’s passing in some peculiar ways, particularly in his appearance, which would make sense given the context of the game.
In addition, there are also some minor rumors about a longer stream of sequels being planned behind the scenes, but we don’t know any specific details for now. Even if that is on the table, it’s very likely that it depends on the success of “Breath of the Wild”. This should give Nintendo even more of a reason to make sure that this release ends up perfect in every way possible. Continuing the franchise for a few years is definitely something that many fans would welcome warmly.