The truth is that the Yeti is sitting on a concrete slab that is broken due to the stress on the concrete from the violent movements from the Yeti.
If the Yeti continued to move the slab would continue to crack and possibly lead to the Yeti falling over onto the track.
The Yeti animatronic is in perfect working order (well, maybe not anymore if they haven't oiled it for 7 years

); it's the concrete slab beneath the Yeti that's the problem.
In order for the Yeti to be operational this concrete slab must be replaced. In order to replace the slab they need to take the track apart.
Will the Yeti get fixed? Absolutely. When? When AK is "strong" enough without Expedition Everest. Right now EE is the #1 or #2 attraction at AK. If you close down EE it will have a negative impact on attendance (it will increase attendance and wait times) at the three other parks as people skip AK.
So once Pandora is open for business we will probably see the Yeti get fixed. But it's like a 9 month ordeal so Disney will wait until EE needs a major refurb for several items before they decide to undertake this.
EE is not only missing the Yeti it's also missing the mist, the steam from the train at the loading area, and the bird on a stick. Just go to
youtube and search for "expedition everest all effects working" to see it in its glory.
Now for the Disco Yeti's theme song:
Hello hello baby sorry I can't move a thing
I haven't been serviced in a while you see, see
But but it's ok there's a flashing light on me
Sorry if you wanted more it's only Disney
It's only Disney, it's only Disney
What more than a strobe would you expect at Disney?
Disco Yeti is my name this mountain's where I stay
I used to be ferocious now I'm just a display
They said they had some plans for me they'd put me on TV
Then hung me on the wall like Mickey's hunting trophy
Stopped moving not proving Disney's expertise anymore
Imagineers build what engineers ignore
Bob Iger's got tigers, rhinos and giraffes by the score
So what's he need a working mythical beast for?
eh eh eh eh eh eh eh eh I'm disco yeti
eh eh eh come fix me
eh eh eh eh eh eh I'm so sick of KC
So ride if you want but there's no more motion
You're just going to find a mannequin
Been fried since they ended my promotion
Left me behind a mannequin
More meets and greets and some brand new suites
So that no one will mind the mannequin
'Cause I'm stuck up above and getting no love
An expensive kind of mannequin
Disney when you built this park you used to be the master
Themed it like a master, fixed things so much faster
But Stitch and Zazu took over and it turned to disaster
On the scale of stellar Wizarding World just passed yeah
Pleasure Island died when they took down the fences
Imagination's now a ride about the senses
But soon you won't be bothered by my disco dancing
They'll block my moves by building a pin trading station
Pin trading station, pin trading station
Inside my ride they'll build a new pin trading station
Stopped moving not proving Disney's expertise anymore
Imagineers build what engineers ignore
Bob Iger's got tigers, rhinos and giraffes by the score
So what's he need a working mythical beast for?
Stopped moving not grooving Luxo won't come out anymore
Nor does that "Incoming!" DINOSAUR still soar
Brakes locking not knocking Test Track cones down onto the floor
'Cause half the time they're still flattened from before
eh eh eh eh eh eh eh eh I'm disco yeti
eh eh eh Jamboree
eh eh eh eh eh eh sees more action than me
So ride if you want but there's no more motion
You're just going to find a mannequin
Been fried since they ended my promotion
Left me behind a mannequin
More meets and greets and some brand new suites
So that no one will mind the mannequin
'Cause I'm stuck up above and I'm getting no love
An expensive kind of mannequin
Ma Mannequin, ma ma ma mannequin
Cause I'm froze in this pose so that nobody knows that I wasn't designed a mannequin
"I guess you could say that I'm happy I don't have to do it all over again!" - Walt Disney