I think the "A" standard is harder to hit in swimming compared to some other sports. The rule is an "A" standard swimmer can swim their "B" cuts, even if their "B" time would not have been selected for the meet. Here is a small breakdown with some conference comparisons. All conference meets are concluded.
50 Free 6 "A" cuts- no one outside of the big 4(PAC 12, SEC, B10, B12)
100 Free 4 "A" cuts-no one outside of the big 4
200 Free 6"A" cuts-no one oustide of the big 4
500 Free 6"A" cuts-1 ACC cut
200 IM 10 "A" cuts-no one outside of the big 4
200 Back 5 "A" cuts-no one outside of the big 4
The MAC is a decent conference for swimming and will have swimmers continue onto the NCAA meet, but very few conferences have people achieving "A" cuts in most events. The SEC and PAC12 are hitting them all the time but they are the ony ones.