Is there a way to disable formatting shortcuts in 4.3?

Yes, there is very well a way to disable these formatting shortcuts. You can do so by using this simple little piece of PHP code.

<?php
function disable_mce_wptextpattern( $opt ) {

    if ( isset( $opt['plugins'] ) && $opt['plugins'] ) {
        $opt['plugins'] = explode( ',', $opt['plugins'] );
        $opt['plugins'] = array_diff( $opt['plugins'] , array( 'wptextpattern' ) );
        $opt['plugins'] = implode( ',', $opt['plugins'] );
    }

    return $opt;
}

add_filter( 'tiny_mce_before_init', 'disable_mce_wptextpattern' );
?>

Hopefully that helps!