I actually don't think it is, but they're doing everything they can to cover it up like professionals would.
At the end of the day, Miller made it really clear that the boys aren't exactly a tight knit group and he's twenty levels above in honesty in comparison to a more corporate guy like Bo Horvat.
Bo's response was really weird as well. He seems irritated by Miller's comments and that's extremely unlike Bo. Bo will usually be a water under the bridge "what's in the past is in the past let's move forward" type guy.
Not to mention what we see in the ice adds up way more with Miller. I'm not saying there's a clear divide in the locker room (I don't think there is) but there are guys that are not gelling and that is for certain.