It totally makes sense.
SLP field isn't stagnant it rapidly changes, neuroimaging gets better and better, there are crazy paradigm shifts in psychology, studies of development, heck even stats! 5-10 years ago iPads in rehab were unheard of, now a lot of clients rely on them for communication and lots of programs rely on them for therapy.
One of my profs refused to use a textbook because she said that by the time its conferred and published, a tonne of new research has already come out.
So I completely understand why they would ask you to retake pre-reqs from a decade ago.