Interesting! I had always thought that sketching deadlines brings the best but timeboxing completes it with its second half of deciding when to start it.
For me the "What to do after you first your priorities" have also been pretty useful. I often have tasks that are important, but for some reason I don't want to do them, e.g. database migrations, production upgrades and things of that nature. Once they're scheduled and I get started, I might be able to bang out my priorities in a few hours. I'd then previously be sort of stuck, because mentally I had decided that that was the day. Now I have things I know I can start on.
Originally, “priority” referred to something singular. In Latin “prior” means “the first”. But we have shifted the meaning.