Early on, the Museum of Modern Art developed a snugly tailored origin myth for modern art itself. This was invented by the museum’s first director, Alfred H. Barr Jr., and mapped out in a began-and-begat chart of labels and directional arrows. The chart had the operational logic of a computer board, but was programmed for limited connectivity, namely between Europe and the United States, more specifically between Paris and New York. Modernism was a hard-wired Western affair.

By the late 20th century, the MoMA myth had lost credibility. Scholars and artists were revealing Modernism to have always been a global phenomenon, emerging across the world in different places, on different schedules. MoMA had an opportunity to acknowledge this reality when it moved into its newly redesigned 53rd Street headquarters in 2004, but chose to preserve, with minor tweaks, the old history that had long been its brand.

Nor will the display be static. The chronological line is likely to include galleries devoted to specific geographic locations (such as, say, Harlem in the 1940s), to art and poetry in the 1960s, to groups of artists (like those surrounding the poet and curator Frank O’Hara), or to zeitgeisty themes. A performance space will be inserted into the mix, and space to accommodate large-scale video installations like Wu Tsang’s 2017 “We hold where study,” a collaboration by this gender nonconforming artist with the writer Fred Moten and the choreographer Ligia Lewis.

And the permanent collection gallery displays will be changed frequently. The plan is to systematically rotate a selection of art in the galleries on the fifth, fourth and second floors about every six months, with roughly 30 percent of the contents rotated each year. By 2022, MoMA will have incrementally rehung all three floors, effectively executing a full reinstallation. Another three-year cycle will then begin.

The advantages of such switchovers are many. Repeat visitors will have fresh art experiences. New histories will get told. Old canons will start to erode. At the same time, though, MoMA’s organizational mettle will be under stress. Big museums are kludgy, slow-moving machines. I suspect the new schedule will keep MoMA staff up late working nights, which, of course, young people can do, no problem. So with luck, much of the shifting and rethinking will be assigned to junior curators energized by the challenge and filled with 21st century ideas, about, among other things, the ethics of determining the cultural breadth of art to be shown.

Finally, an exhibition called “Betye Saar: The Legends of ‘Black Girl’s Window,’” will at least gesture toward putting to rights a longstanding omission. Ms. Saar, now 92, is many decades overdue for a full career retrospective. Disappointingly, the planned show, consisting of 42 early prints by Ms. Saar, is not that. But at least it gives a major artist the solo spotlight on prime MoMA real estate.

Even more significant, in the long run, is the fact that MoMA has acquired the Saar prints for its collection. Acquisition is everything. Short-term shows come and go. Their presence can signal a genuine change in an institutional direction or merely paper over entrenched habits. The only solid gauge of commitment is when something is brought into the collection, and put on view in the permanent galleries. And specific recent acquisitions that will debut when MoMA reopens in October are the surest signs of MoMA’s intention to widen its sights.

We’ll see the first painting to enter the collection by the Spanish-born, Mexico City-based Remedios Varo (1908-1963). In addition to being a mesmerizing image — it suggests a high-fashion version of “The Handmaid’s Tale” — it adds to the small number of female artists in the museum’s sizable Surrealist holding. And there’s a newly acquired painting, from the early 1960s by Hervé Télémaque, born in Haiti. Mr. Télémaque, 81, has lived and worked in New York, Paris and Port-au-Prince, and his painting embodies the spirit of three. It has AbEx sweep, Pop verve and an otherness that makes it a world of its own.