The issue here would almost have to come on the actress’ end, perhaps over a scheduling problem if USA’s Shooter ever gets to air its first season.
Otherwise, I’m betting Patty will be back in Barry’s life at just the right inopportune moment.
(Case tangentially in point: Supergirl is now on The CW.)
Whatever this “everything” is that Shantel VanSanten spoke of with Monkeys Fighting Robots, I have to assume that it will indeed get worked out, since I can’t imagine there is anything Greg Berlanti & Co. want that doesn’t happen.