TotK will clearly have a historically huge launch. It's not even up for debate. People can make ages long analysis about the franchise sales history, it really doesn't matter.
The past does not apply here. No other Zelda game was as anticipated as this one, no other Zelda game launched on a highly active userbase of this size. TotK is not going to randomly alienate the fans of BotW. It's going to sell way more than 10mil first quarter and easily above 20mil lifetime without issues.
The trailer showed a lot of stuff, new enemies, new vehicles, new mechanics, new bosses among other things. Every trailer showed more and future trailer will keep doing that.