“So has the existence of this video led to a credible push in the USA to outlaw criticism of Islam?”
The people who are actively seeking to destroy this country are too smart to try to directly pass something like this in USA right now.
Laws forbidding the criticism of Islam and blasphemy against it prophet will be enacted by the UN, then the USA will be made subject to UN law through the Trans-Pacific Partnership and other such treaties.
In their dreams. Treaties do not trump the Constitution.