The refurbishment is most welcome, the retheme to fill it with Marvel themed art is an interesting choice, but since Disney has committed to the Marvel Universe long term, it does make a kind of sense.
It is bound to turn some people away, though as it's art themed, rather than hero themed, it may not be as bad as we're thinking it will be. It will also attract others, Marvel fans and such, so the hotel will still do well.
Losing the 1920s style glamour is certainly a shame, but this is more in-line with Disney as it is today.
Especially if you consider that many of the "golden age of film and theatre" icons are going away at Disney parks across the globe (see the Tower of Terror retheme, the Great Movie Ride closure and such as examples).