Home Sharing has never updated play counts on my iTunes server from any iTunes client (ATV4, ATV3, or MBPro/iTunes client).
I have tried it with many versions of iTunes between 2 macs.
I tried when I got my ATV3 a year ago.
Also tried it with my new ATV4 a couple weeks ago.
Never had success.
Like many, I've confirmed many times (unchecked and rechecked) the iTunes preferences to update play counts from clients.
I had submitted a bug report when I first encountered the problem ( i think a couple years ago).
When new versions of software come out, I try it again each time, but it has never worked. So I abandoned HS and just plug in my iPod when I want to listen to media on other computers than my iTunes server (I have more than one mac)...
My iTunes server dedicated mac connected directly to my stereo and TV. so it is plugged directly into the TV HDMI and stereo thru audio jack, and I play directly from the mac without using ATV.
I was explaining my issue in another tread, and Winston replied and mentioned that this issue was showing up in other posts. (thanks Winston!)
So, I'm adding to the chorus for whom it is not working.
Good Luck to everyone!