The Speaker invites the President to the House for the State of the Union address. The Speaker is NOT inviting the President to a public televised event. There is no way she's going to give the orange shitstain is going to walk into HER House, and have a platform to speak to the nation, and in a grand spectacle.
You haven't thought this through, have you? If Nance blocks Trump from giving the SOTU it will show the American people she is attempting to silence the POTUS. Is she afraid they might like what he will say? Afraid she might end up looking petty and partisan at the expense of the people? I hope she tries it.
She's not silencing him. She suggested he revert to the original SOTU, format which is the President put the address in a letter to Congress and they can publish it and the American people can read it.
It takes a lot of security and government workers to set up and broadcast the SOTU, and Nancy refuses to use unpaid labour to give the President this wonderful forum. Her House, her invitation.