Will the works really be gone for good when the shows end?

According to Randy Kennedy, writing in the Inside Art column of The New York Times (“Made Not to Last”,  July 10, 2015), this summer a number of New York City galleries are mounting shows of works painted directly on the gallery walls. When the shows end, the works will cease to exist—either painted over or, in the case of the Andrew Edlin Gallery, demolished along with the building. However, considering the high value of art, one suspects that fairly soon conservators may be called upon to try and recover these murals.