It is not real 4K in any material way due to having a final master at 2K. Studios have upscaled the 2K image to 4K and retouched the content for your 4K UHD TV. You should see some visual improvement over a standard 1080p Blu-ray. Animated CG movies scale up very well and can look like Real 4K. Check the information below to see if the studios have upgraded the video with HDR or added immersive Dolby Atmos or DTS:X audio tracks.
Animation Rendered in 2K (2.8K Live-Action Scenes)