60hz/120z/whatthefuckever doesn't matter for TVs with gaming.
You are not going to push more than 60hz on a HDMI cable. Those are emulated refresh rates. If you connect a computer, you'll only see the 60hz option (honestly, on a lot of cheap 4k tvs you'll only get 30hz) and it will look like shit when moving anything around. True 144hz monitors use a dual link DVI cable for a reason.