So you'd be creating a game inspired by the mechanics of those games, sure, but what's beyond that? There already are 2D Zeldas, Dark Souls and Earthbound, what new would your game bring to the lot?
Do some research. I’m sure you could find a hundred games like that on the Steam store, what would make this different?
For the record, different and new isn't the only way to go. Some games out there succeed by just doing exactly as the formula says, and doing it incredibly well (from what I hear). Also, 2D-Zelda + Earthbound + Dark Souls sounds like a game that I totally would play, simply to experience a 2D-Zelda + Earthbound + Dark Souls experience. (Also because I'm interested to know how you intend to combine those games. They're not too different--which means you could potentially get some very clever ideas for your gameplay out of it~)
If it was to the same quality of those, of course. It's all about that certain something, I was thinking about what a good Zelda like game made today would be like, yesterday. Dark Souls actually fits in very well with Zelda, there's lots of caves and dungeons, and big boss fights.
I think people will play a mash up of any popular genres. For example my game in progress, incorporates elements from the history of gaming. Question is, will you enjoy it? if you don't then don't do it. Everything sounds great on paper. Try a prototype of the simplest elements first, throw out your ideas easily and ... follow the fun. If something is fun, do more prototyping around that. If something is not fun, ditch it. Be organic.