Personally, I don't believe that what he said will come to fruition. But what the maitre d' was describing is not what several of you assumed. It's not that people would be assigned to the "formal every night" dining room. It's that every night, anyone who wants to dress formally would be seated in that section THAT NIGHT with other people who wanted to dress formally THAT NIGHT. Then no other dining area would have formally dressed people, just that one section. You could ask to be seated there once, twice, three (etc) times during your cruise, or zero times.
But I don't think it will happen.