In my opinion, most of the high end chefs have done okay in Las Vegas. A lot of resorts start out with a restaurant list and adjust that list in the first year. But it is not unusual to see the chef of a closed down restaurant reopen at another location with great success.
I think Wolfgang Puck, who has about 10 restaurants here, has only closed one of his establishments. And that was pretty much in the peak of good financial times.
It is also my opinion that your example has 2 unique factors. One is that the economic climate is not doing very well, which affects risk on many many levels. The other unique factor is the City Center stigma. I think any given City Center restaurant would face different challenges and goals if it were to have opened in the Wynn, MGM, or Harrah's property.
I do find your question very interesting in another way. Instead of "what happens to high end restaurants in City Center", it got me to thinking about what happens to a poker room, nightclub, high end retail store (that nobody shops at).
Sorry, I don't have any restaurant answers for you.