Mr. Rosenbaum, and the folks at NPR have brought forth an interesting question. Is it right to stage fake weddings for Alzheimers patients (who will enjoy them voluntarily) or is it abhorrent deception? It's a lie, plain and simple.
At first I thought it would be no more harmful than a play. What they are basically offering is theater. The difference is, no one present realizes that it is fiction.
They leverage the effects of a crippling, and eventually fatal, disease in the name of entertainment. This is not something that would be acceptable for a day care to do to kids. For example, they can't tell them Barney is real and that he will bring them presents if they are quiet, with the knowledge that they will forget by naptime). Fiction that is not presented as such doesn't usually work out for fully functional adults either (that War of the Worlds broadcast was kind of a disaster). The staff of this home demeans their patients by treating them in a manner that would not be acceptable for other people and use their illness to justify it.
What they should do is treat their patients with the care and respect worthy of someone who is cherished by many and who is slowly being lost.