You don't think they'd have a long enough time jump between S3 and S4 for Iris to move on, do you!?!? If that happens imma egg the writers houses -__-
I highly doubt they’ll have Iris move on in season 4
I think the time jump will be the usual 6 months but even if they do make it longer I don’t see it happening.
The first time Barry proposed to Iris he told her that story of his grandfather going off to war for years and when he came back his grandmother was waiting for him. I truly believe that was not a random story they put in for kicks. At that point the writers knew how the season would end. Barry and Iris’s separation would probably mimic that story.
At the most they’ll introduce a new male character who is clearly attracted to Iris and will put the moves on her. Iris however will shoot him down cause only one man has her heart.
There is no need to worry sweet anon <3