After we defeat oryx in the story mission and she refers to her queen, my theory is that she is referring to Savathun. At first, I thought she was referring to the awoken queen. However after reading the grimoire again I'm torn between possibly the awoken queen being Savathun or she's an evolution of the human race. The reason I think the awoken queen "[b]MAY[/b]" be Savathun because in one of the verses of the book of sorrow she (Savathun) tells oryx that she needs to grow away from him and leaves. She could have possibly become the awoken. That's just a theory though. The only thing I know for sure is the Eris refers to a queen during the last cut scene, which is strange.