I also have to respectfully disagree ... but ... with the automatic approval.
As I mentioned before: everyone can make mistakes, whether they are large mistakes or an oversight or just bad luck that a typo passed unnoticed which would only cause a problem in a very specific (or rare) case.
In my experience with testing extensions, I have come across errors which I only found through luck (call it bad luck for the trusted author). It's part of the process in trying to ascertain that a validated extension will not cause an error on the board.
It doesn't imply that there will never be any errors as it's impossible to test on all php or database systems (nor versions) but it's a minimum standard to be reached (which BTW doesn't even imply that the validator can test all features/combinations). Sometimes an extension can be tested in 30 minutes but sometimes it takes days. (and I'm talking about functional testing only).
As to styles (with which I have no formal testing experience) I can imagine testing being a lot more tedious and errors being a lot more difficult to find.
The solution to the "waiting" problem has been mentioned in this topic and is the same solution which is (in many cases) applied with extensions: making the new release version available on the author's site or on Github which has the added advantage that the style (or extension) will be "tested" by more users.
Basically it's the same principle with RCs before they are submitted for validation