Is anyone else bothered by Barry dating Linda in the TV show? Now we don't even know if Iris has a brother, I think they've been very careful in being vague on if she was an only child, so they could still introduce him and Wally in the future. So yes, this is a completely different reality, but whenever I see them together something feels wrong to me.
It's his potential nephew's wife in a different reality. I can't think of a good analogy to compare this to when I'm trying to explain my uneasiness to my family. I know I should relax and just enjoy it, but it will take a while.
It is a TV series that references canon but doesn't have to adhere to it.
For all we know if they want to bring in Wally, they make him the son of Barry, rather then the nephew.