Hi hello I share this headcanon and I have proof.
The fade prison is the first instance of Rook thinking the companions are dead, right? But every mage knows that what we see in the fade might not be literally true. It's Rook's regrets that leave them trapped there. Bellara or Neve saying "You picked me to die" isn't true, because NEITHER OF THEM ARE DEAD.
So I sacrificed Davrin in my first run because I have never played the Mass Effect series and I didn't know T_T. I got to that scene before the final battle where Rook can go to Davrin's room to Remember Him, and it was all about his sacrifice and how he will never be forgotten, thanking him for what he did for the team.
Ok, fair enough I expected as much when a companion is presumed dead, but that's not what happened when I sacrificed Harding.