FWIW, our school says they can't excuse the higher level kids from all the review because the kids sometimes score poorly since the test isn't aligned to what they are learning this year, but more to what they learned a year or more ago.
I think this is why the district now refuses to subject accelerate (or even differentiate in the classroom with anything more than "enrichment" of concepts being learned). They are worried the accelerated kids will forget the concepts that are on the test for their grade level, or that there will be "gaps" and they show up on the test.