I'd suggest that if the oil was supposed to be shaken before pouring, it would say so on the side of the tin. Let's see some hard evidence about this, not unsubstantiated passed-on advice.
Puts me in mind of the adage about not turning a piston engine over backwards by hand because it will destroy the vacuum pump vanes. Absolute nonsense - I've got it in writing from Parker Hannefin, who make the things...