Whether an uncompressed digital source file was used for the LP mastering is another matter entirely and depends largely on the producer of the project.
Thank you Ralph (@atmasphere) for this very informative post in its entirety and for your particular comment above. Moving on from redbook vs vinyl, do you have any thoughts on the dynamic range of high resolution files (considering they were produced to take advantage of the range) and its performance in a low-noise, caching local server with a stellar clock and architecture? Yes I know that many digital front ends aren't up to the task, but there are a few that I believe are.