I think it would be quite funny if at E3 this year if Nintendo did a Zelda U trailer with a release date. 
It would be hilarious if their previous comments regarding the 'delay' was all just a big troll.

If you look at the start of this trailer for Dumb and Dumber To: https://www.youtube.com/watch?v=AmlEj40tr6Q

Would it not be funny if if Nintendo did a similar 'Gotcha!'?

Following this announcement they reveal the actual title ect.

Note: this is very unlikely to happen. Nintendo is likely focusing on games that they are releasing this year, and announcing some new titles for release during the 2015 fiscal year.
The question is: would you find it funny if Zelda U's  'delay' was just a troll?

I would find it extremely unfunny.

Then I would cry for joy.

In that exact order? 
Or at the same time?

If I recall the exact quote from Aonuma correctly, he never explicitly stated 2015 was 100% not gonna happen. He said that they thought of new ideas that they felt would be good to implement and that this could affect the ship date. I'm paraphrasing from memory here, but I definitely remember Aonuma's comments being fairly nebulous.

I'd love if it happened but I don't think it will. I don't know WHAT the holiday title is gonna be, probably Mario Maker and Splatoon pushing with the usuals bar a surprise Metroid reveal or something, but I don't think it'll be Zelda.

"As I said in the video, we would like to take this time 
so we can bring you a very special experience, by making the ultimate 
Zelda game. Since we’d like to focus on developing the game we’ve 
decided to not show the game at this year’s E3.

Thank you for your continued support, and I hope you’ll look forward to the game!" - Aonuma

He did say that it would not be featured.
The point of this thread was to say wouldn't it be funny if it were just a troll.

Regardless, the likelihood of the game actually appearing at E3 this year is practically none. 

Well to say the game isn't even appearing at E3 and that we haven't seen it or heard anything about it in the best part of six months...that seems pretty unlikely.

I have stated in the thread that this probably will not happen.
This is proof that it probably will not happen:

"As I said in the video, we would like to take this time 

so we can bring you a very special experience, by making the ultimate 
Zelda game. Since we’d like to focus on developing the game we’ve 
decided to not show the game at this year’s E3.

Thank you for your continued support, and I hope you’ll look forward to the game!". - Aonuma


However, the question I was asking is: 
If it were to happen, and Nintendo outright said that they were just trolling and made a joke about it. Would this be a funny move?

It would be very stupid.

What you have said just now - if we are to go by Nintendo's actions as of late, and analyse what you have just said. All signs would point to Nintendo going through with this joke. 

they never said the game wont be released this year though but i highky doubt it, It would be like the first console zelda game that isnt delayed