But why would nintendo want to release 2 zelda games on wii u in the same year? surely they would want to release it in 2015 to bridge the gap left by starfox zero. Unless of course it wasn't ready because the project only began earlier this year.

No
I dont believe it

Can someone explain what the other rumour was of this game regarding the NX?

* Nintendo fired some staff and hired new developers

Nope nope and nope. Had they fired staff, specially from the team developing Zelda, we would've heard about it. But it still wouldn't make sense since Nintendo rarely ever lays-off, let alone fire its employees.

Alot of those issues do seem to be indictive of "first time open world development issues" , that alot of Japanese developers fall into..

I can buy the "moving between dungeons in the big world was boring" part based on what we saw at the game awards 2014. It looked like an awfully barren world at that time. I wouldn't be surprised if the delay was to make the world feel more alive and have things to do since Nintendo still kind of has to wrap their brain around a true open world concept if that's what they're doing. They've yet to do that,so there will be learning curves for them just like with their HD development issues at the beginning of Wii U's life.

At the end of the day the bottom line remains the same though: this game is of extreme importance to Nintendo and they aren't going to release it until they feel they can truly deliver on a next gen Zelda experience. I think they will. I really don't see this being another TP or SS where "big changes" were promised and at the end of the day it ended up being really just another great but same ol' Zelda game. I believe they want to do something truly invigorating for the franchise this time, and that is unlikely to be without its hiccups. So I'm sure that's the reason for the delay. On a more specific level though, yes it could be open world issues they needed to sort out IF they truly are going the open world route. 

This is the correct response. On top of everything else wrong with it - most notably Tantalus having worked on TPHD much longer than the leak assumes and the fact that Aonuma would be dammed if he made a Zelda game light on plot - Nintendo simply doesn't lay developers off. The ONLY way that could be arguable is if the game was delayed in the Kimishima era since we've yet to see his stance, but Iwata was alive and relatively well when the game was delayed, and Iwata took several paycuts to avoid layoffs. Even then Kimishima would likely hold the same stance as Iwata there. The only reason they'd fire somebody is because of conduct detrimental to the company such as leaking info; following Aonuma's orders is not (necessarily) detrimental although you could argue that about SS and TP's filler. Zing!

Wow.... so they delayed the game because it kinda sucked? gameplay/story wise.... ouch.
That explains why its takeing so long though, that stuff isnt nearly as easy & fast to fix, as performance or bugs.

I don't think it's anything like these rumors. They just wanna make sure it's going to be a really special game. Don't Zelda games always delay?

If the game is basically finished, then why don't show some actual gameplay to make people excited?

I don't believe these rumors