Not unlocked, on Verizon. About a week ago I rolled back updates and installed the open beta. I rarely get those iPhone reactions, so I didn't know if they were working or not. tested it out with my daughter and her iPhone a couple of days ago and it worked. I decided to go back to the Samsung skinned version because it's easiest to update, and the iPhone reactions were still there.
Others have reported that they had the reactions (on the open beta) for a while and then they disapeared. Did you have them straight through since January?
There are also people with the open beta who don't have the reactions yet.
I don't think the app variant matters, Samsung or otherwise, and everyone will eventually get the feature. Google takes foooreeeeveeeer to roll out server side updates to its apps.