In my experience I have never had a hazing issue when glazing matte prints. The reason, I believe, is that the ink is absorbed into the cellulose of the paper where it dries much faster. With photo paper that uses a receptor coating the ink sits just above the paper surface in a swellable coating. It pools more requiring longer drying times compared to matte papers. I think you may be right about the darker areas absorbing more energy from sunlight possibly generating more out gassing.
I have never used a print coating on paper prints only on canvas media. I would think that the ones coated with the sealer would prevent out gassing.
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