In short, they can right now. There's an Association of Art Museum Directors. Usually, the consequence for selling art to pay bills would result in that museum

In short, they can right now. There's an Association of Art Museum Directors. Usually, the consequence for selling art to pay bills would result in that museum being censured by the art museum directors. They announced a couple months ago that they are allowing a 2 year reprieve from those censures due to COVID.