That is a very real possibility. And if I were Team Flash (or HR), I wouldn't tell anyone about it.
It's a plausible scenario and I like it. I always thought HR's days were numbered anyway. What greater way for him to leave than to die a hero, saving Iris's life?
I guess we'll see next week.
Except Wells19 was ranting about how he screwed up and got Iris captured.
If this switch was made then it had to be off camera, possibly after Iris went to Earth 2, Wells 19 went there and made the switch after Iris had her fun talk with Joe. However Iris as WELLS19 would then have been doing the rant about his screw up.
I don't see how Wells19 could made the switch at any other time.