"Considering your world's magic, that would make sense." Strange has no idea if Solas could still do the dreamer magic he did back home in the carnival, but if he can? Then that's definite points to there being some trace of the Fade here.

"I wonder...if mages from your world are still tied to the Fade, then that connection exists here. Could mages like myself use that to find a way to connect to the Fade?"

It is an intriguing idea. And one that Strange isn't entirely sure can happen in the first place, based on his massively skeptical frown. He's going to bring it up anyway, because that's what magicians do: they talk, discuss theories, argue with each other, and make all sorts of discoveries in the name of magic.