Based on all the evidence I have seen, I no longer put my cameras, at any time of the year, within 100 yards of my stands....and never within the same funnel, or up/down a trail from my stands. Good places for cameras are often not good stand sites, and vice/versa, anyway.
I think you're on to something here
. I wonder if the snow track folks would like to take a challenge and see if it's the cameras.....or the constant intrusion on the area? IMO.....when you set a trail cam up on a trail.....you're asking for trouble. You have to go check it (more scent). You're leaving scent where it shouldn't be (where you expect to see deer).....and taking a chance that your flash "might" spook them (or a particular deer).
So I'm wondering if they are avoiding the camera flash.....or the constant scent left there by checking the cams????
Introduce a pleasant stimulus (food - minerals) and I'm betting they'll tolerate more than they would on a trail. I'd sure never know if they avoided them on a trail, or not.