Yes the power comes from the bottom from what we see in the pic. I told the client that this is going to be an issue wall mounted and with the TV not on a stand to hide wiring. Power wire def wouldn't be hidden unless some changes were made.

I was originally thinking the shelving was custom built as this is a 2 million dollar home. But maybe not. I did notice a bunch of metal peg inserts where the shelves could be adjustable. That to me almost seems more like a premade deal them custom but idk much about cabinets lol.

I also had assumed it was anchored to the wall but that is a good point that it might not be. I also assumed the backside would be flush up against the drywall. Maybe not.

I figured i would just locate the studs above the shelving. Take some measurements and the stud should run down the wall behind the shelving. I could drill a small pilot hole in that area and see if I hit a stud. I also have a small boroscope camera I could drop thru a pilot hole to help locate studs.