...and replaces the game's EA Download Manager authentication system for the Ultimate Edition with the system used by the Origin service.
Sorry, that is not quite right. The 1.05 patch installer will fix a bug with the EA Download Manager delivered version of the game. This would only occur if you had purchased the game from the EA store before the Origin service was launched. We have had this patch in Beta for some time and customers have used the earlier versions to resolve this problem. This problem no longer occurs if you buy the game through the Origin store.
There have been no changes to the game's authentication system. The good news is that we have fixed a number of DLC authentication issues in the update.