Does Hair Loss Reduce After Shaving Head?

No, shaving your head will not affect the rate of hair loss.  Hair loss is most strongly determined by genetics.  Keeping the hair shaved may reduce the noticeability of shedding as the hairs are shorter, but otherwise will not contribute.

Unfortunately, shaving your head will not decrease hair loss. For the most part, hair loss is caused by genetics, or medication, or a number of other issues. However, some short hair cuts can help to hide hair loss where it sits. There's lots of information online for suggested haircuts to help hide minor hairless.