I don't believe that is true.
The phrase you are referring to (which has a thread where the teleprompter output is shown containing that phrase) was on the teleprompter during NEWT GINGRICH'S speech.
That means one of two things. Either they were assured that Cruz would endorse Trump, or they were trying to leave him no option but to endorse without looking like a backstabbing liar.
Others have posted that Cruz went off script too. So its confirmed by people there. Yes the screen cap was Newt’s based on what they expected Cruz to say.