You can't really compare the two, because the Pompidou Center in Paris has a permanent (and overwhelming) collection.
The Pompidou Center Metz is a showcase for things from the main and other museums with rotating exhibits. When I visited, gallery 1 was supposed to change after 6 months, gallery 2 after 9 months and gallery 3 after 12 months so that people in that part of France would have continued access to varied works. I have read since then that the museum has been so successful that they have already decided to extend the length of the exhibitions.
Also, I should point out that the things exposed at Pompidou Metz don't all come from Pompidou Paris. Some of the things I saw were from places like the Orangerie and Orsay, among other museums.
The Louvre annexes in Lens and Abu Dhabi will operate the same way.