Having recently replayed through ARR and 3.0, the BoL seemed to mostly serve as some form of Ascian repellent. Not having the BoL from the time Midgardsomr takes it away to the time you regain it (with multiple primals in between) doesn't affect the WoL at all except when an Ascian is involved where they comment on the strength of your protection/their ability to inflict harm upon you.