The "Mastered in 4K" titles from Sony back then were before there was an UltraHD Blu-ray standard so Sony squeezed a little more color information on a Blu-ray and supposedly matched the downscaling of the 4K master to the upscaling done by the player to have "more accurate" 4K upscaling. Anyway, Sony has a proper 4K master of this and it can already be streamed in 4K (without the HDR + Atmos remix) in some markets.
Forgot to add it yesterday but here’s the inside and discs if anyone wanted to see. Could be better but the outside alone makes it a worthy upgrade. That and the UHD disc being another top tier catalogue UHD from Sony with probably their best Atmos remix too.