I was recently told by BU that they recommend the applicants to have recently been admitted in a Master's program, or be fresh out of college, to ensure that their courses were "up to date". That was the only time I've heard of this, so I'm not sure how prevalent this is.
I took the brunt of my pre-reqs in 2007-2008ish, so if that's "out of date" I'd be a little ticked.