I made the following post in the Warner Archive Announcement thread:
Last night, after receiving another email that indicated that Rio Bravo and East of Eden 4K/UHD release date has changed again from July 18th to August 1st, I did my usual checking around other retailers. Movie Zyng, Best Buy...
Yup, I already watched it and will preorder this 4K/UHD release as soon as the link goes live because the disc should look even better than that 4K digital with less compression.