It's hard to believe this administration will rush to the states' side on this issue. Missouri cited the unavailability of sodium thiopental in announcing its change to propofol, a switch that didn't require legislative approval. Oklahoma could do the same but that would surely bring legal challenges, as happened when we went to pentobarbital after supplies of sodium thiopental dried up.
When might propofol be used in Missouri? Given that the Show Me State will first have to show that one execution drug is as good as three, expect it to be a while.