Six years ago, the director of Hong Kong’s M+ museum, Suhanya Raffel, told cultural strategist András Szántó, in an interview for the book The Future of the Museum , that in the years to come museums will need to “stand together and work to help one another to deliver a more sustainable baseline.” Collaboration, she went on, “will be a key aspect of the next chapter of museum work.” Her words seem to have been prophetic: on Friday morning in Hong Kong, M+, the Museum of Modern Art in New York, and the Centre Pompidou in Paris announced a wide-ranging cultural alliance unprecedented in its scale.…