So how would your Inquisitors react to learning Solas' true identity?
I feel like mine would think a lot more about Solas makes sense, but she'd really start doubting everything she ever knew about the elven gods. I mean, the Dread Wolf kissed her like a drowning man, had little self control when it came to romance, once set his own coattails on fire accidentally, enjoys frilly little cakes and snorts when he laughs. So much for a terrifying trickster god. 
I feel like... Katori would then be the one making considerations... I think on the one hand she would be kind of relieved just to know the truth... Once she did, indeed accept that it was the truth, which might be a hard sell in and of itself. She definitely would think it made a certain amount of sense and, because so many things about the Dalish have proven to be wrong, she would probably be able to eventually come to terms with her boyfriend being the Dread Wolf. On the other hand, it would depend on what else comes with the knowledge of Solas's true identity.
With as sweet and good natured as Solas seems, especially in a romance situation, I have a hard time picturing Solas's plans being truly nefarious. He seems wholly concerned with the "greater good". As evidence by his break up with a sure thing, someone he truly loved and would have willingly lost himself in, at least momentarily, and he traded that for the unknown path that he feels he must walk alone. He is truly a tragic (hero?) and I think that is part of his beauty, but... Whatever his plans entail... I think that is going to be what either makes or breaks Katori's acceptance.