You need to take a deep breath and readjust. I think a lot of people thought there was gonna be some momentous new trailers or something and got let down hard. There isn't going to be anything like that and it's not a red flag. In fact this is pretty a par the course with highly anticipated sequels like this and I ,and I'm sure many other people, were expecting this. They don't' need to sell us on anything, they just need to let us know when it's coming out and tease us a little. This game is going to sell no matter what. But what they don't' want to do is spoil anything that will lessen the impact on launch day.

I really hope they are holding their cards close for a big surprise, but if this is just BotW DLC with "more".... ooof we"ll see.

Use your brain and think about how unlikely that is. Nintendo would have imploded behind the scenes while we heard nothing on the game they have been making for 6 years. The most likely scenario is that they added a huge twist to the core gameplay they don't want us to know about. Think about it, each Zelda game usually has a core mechanic that it revolves around and it's usually some time shit or dark world shenanigans. My guess it's some combination of both.

I want.... a Zelda game, with Zelda dungeons.

You mean another an OOT/ALttP rehash? Sorry, you aren't gonna get that, but I would eat my shoe if there isn't more long form dungeons of some sort. Or maybe more interestingly to me one big as dungeon that you explore in chunks. And my guess is instead of having items gate your progression it's gonna be abilities related to that arm and time shenanigans. There are so many possibilities. Even if it's not what you want it to be it's not gonna be a half-assed sequel, that is for sure. Nintendo have always tried to some new and innovated with their mainline games.