As for what "haptic buttons" means, I'm not expecting anything significantly more advanced than what's in the Steam Controller or even a touch screen keyboard on cell phones. You get a little vibration when you press it. They can program it to varying degrees of intensity and have a motor on either side and that will provide a nice effect.
I'm sure there will be some option(s) for physical traditional controls, but I don't think most people would need to feel a button underneath their thumb for the input to be intuitive. A number of genres (not all) would probably work well with 4 regions mapped around the analog nubs.
And in all honesty, if this is primarily a handheld, we need to accept the times we live in. Most kids and casual adult gamers are fine with just a touch screen. The type of configuration pictured would already offer many more options than those gamers are used to. Nintendo are trying to capture a wide audience of everyday people. They'll have options for hardcore gamers, but why would they release a traditional controller when they've said time and time again that they're not competing in the high end market? If they can make Zelda, Mario, and Metroid work with 2 analog nubs, scroll wheels, and a touch screen, that's cool by me. I've been playing games a long time. In a reductionist sense, it boils down to pressing buttons. I welcome new types of input just as much as I welcome VR.