All directors are, but are all shareholders? I just did a quick check and it only seemed to list people with significant control, not all shareholders. Unless there’s an area I’ve missed.
Of course, this list may well just be other companies that are overseas and you can't drill down into their owners.. ;-)
And this is a crucial difference. UBOs (Ultimate Beneficial Owner) registries list, well, the ultimate beneficial owner(s), the person at then end of chain. See examples in twitter thread [0] (already linked a couple of times).
a new company won't have one at all