Oklahoma also selected Kevin Stitt as their republican candidate in the gubernatorial runoff. He said he wouldn't have signed the $474 million tax increases to fund the teacher pay raises this past year.
Oklahomans were pretty split last year during the teacher strike. The state's government came up with nearly half a billion dollars in tax increases prior to the strike to increase wages. The OEA decided that wasn't good enough and went on strike anyways. Two weeks into the strike, they realized they weren't going to get anything else and they called the strike off. Both sides were upset and there was even talk of replacing the head of the OEA.
I'm not sure if the pro-education candidates won due to shift in sentiment, or if they won due to random chance.