It would be a nice set up, for controlling the narrative (which is what this is about).
Will it kill momentum - maybe - but often these things can have the opposite of the intended effect. There’s a lot of the story here that is unknown, but that won’t stop the media from going crazy right off and the attention given to this will be primarily in the first hours.
It definitely doesn’t help.
The media is going to use this as a cudgel to try and silence the President.
The narrative will be: "Trump's reckless rhetoric and attacks on his critics are inspiring his supporters to commit real violence.!"