From what I have read Fender used the heal adjustment (and kept it on most US models) to avoid the ski slope problem they could get when the adjustment is at the headstock. I have never had it happen to any of my basses yet and I hope it never does cause its a pain to fix.
I don’t have a clear view of the base of the neck in the pic but the pickguard is not the original and makes it harder to determine what it is. Even the newer models with the pickguard cutout never seemed large enough to adjust the heal nut and I ended taking the guard off anyhow.
EBMM’s wheel adjustment was a much better idea for the heal. Old Leo had his hands in that design too so maybe he was improving from his previous venture.