No. I'm saying that you invite them to appear, as chairs normally invite witnesses to appear, and you extend them the courtesy of being flexible about when they might appear, as chairs normally extend that courtesy, but if a witness refuses to appear, then you have the threat of telling them that you are empowered to summons them. I hope that you would not have to use that threat, but if you do need to use it, the motion empowers you to do it.
You begin with the invitation, but if witnesses refuse to appear, you are empowered as chair, if this motion is adopted, to summons them.