It's complicated. If you are using the containerd backed image store (opt-in still) OR if you push with "build --push" then yes.

The default storage backend does not keep compressed layers, so those need to be recreated and digested on push.

With the new store all that stuff is kept and reused.

That's true, but I'd assume the server would like to double-check that the hashes are valid (for robustness / consistency)... That's something my little experiment doesn't do, obviously.