I imagine it's the case of the WoL simply assigning the body of Fray to our darkside since it has probably weakened after revealing its true form in the 50 quest. The darkside had to take on the form of Fray in the earlier levels because it was not strong enough to take on it's own reflection of us until our feelings and disdain became even more intense.

I'm disappointed as well that our Living Shadow just summons Fray when it should've summoned us but I just assumed of the above reasoning and more likely technical limitations.

I'm frankly more astonished of the fandom and support of Fray. Clearly showing that people probably didn't really pay attention to the 30-50 story. But I guess that's unsurprising since we also seem to worship Haucherfant and Zenos for whatever reason.
But perhaps it's more the fault of the devs for not keeping the story consistent and clear. /shrug