That also has interesting consequences as it would mean Amell’s Flash is with Candace Patton’s Iris and Gustin’s Green Arrow is with Emily Bett Rickards’ Felicity.
It sounds crazy but remember “Crisis On Earth X” paired up Melissa Benoist and Stephen Amell.
It’s also possible the only folks that switched roles in this scenario are Grant Gustin and Stephen Amell, and everyone else is in the usual roles they’d play on The Flash and Arrow.
Flash and Green Arrow may be the only characters we see from this world in the crossover, so these questions don’t have to be answered.