I would wager that this is only true in the sense that what colleges DON’T want to see is a previously straight A student slack off and get “senioritis” and start failing all of their classes. That is not at all the case here.
And while this NOT meant as any sort of criticism of the OP at all - I realize it is the result of the pressure cooker that high stats students find themselves in - what is wrong in the world where a student feels compelled to explain the fact that they got TWO Bs because of a DEATH IN THEIR FAMILY. I am both fascinated and horrified by the world of high stakes admissions.