Found my solution (below)
function custom_user_profile_fields($user){
?>
<script>
(function($) {$(function() {
document.getElementById("send_user_notification").checked = false;
//JS HERE
});})( jQuery );
</script>
<?php
}
//add_action( 'show_user_profile', 'custom_user_profile_fields' );
//add_action( 'edit_user_profile', 'custom_user_profile_fields' );
add_action( "user_new_form", "custom_user_profile_fields" );
