This is all interesting stuff. So if anybody has an explanation please share.
My Understanding is:
Health is the single most reason for shedding early.
and Testosterone levels start the shedding process but usually occurs the same time every year.
Soooo!
Maybe with no stress and lots of late born doe fawns. ??
Not enough bucks to breed the fawns causing extended breeding season.
Actually you have it backwards...
Stress causes earlier than normal shedding. When you see bucks holding their antlers into springtime, they are healthy and show sign of a less stressful rut.
Ideally, a buck will hold his antlers until the new grownth causes the hard antlers to fall off.
As for the late born fawns...it could be a matter of many different factors. Most of the time the really late born fawns are due to the mother either missed conception earlier in the fall, or the mother could have been a young deer and wasnt receptive until later in the rut (ex: Jan-early Feb)