As someone that’s worked with the 4K Blu-ray of Solo, yes you can get a 10 bit flat image. It allows for a ton more flexibility in grading. There are ways of chroma upsampling and flattening footage yourself which I’ve had to learn for regrading the prequels, but having the real thing will always be better.
Hence, I’m definitely waiting for the 4K Blu-rays to work with for my prequel regrades.