Fair play to him, he obviously backs his ability as you'd expect from someone working in elite sports.
My preference would be to keep ETH one more season and see how McKenna does in the EPL. Actually let our new directors begin sorting the structure out to make our next head coach appointment successful. But if the decision to sack ETH has already been made, my first choice is a punt on McKenna.
He knows the club, I actually feel he played a large role in the positive aspects of Ole's tenure, which was ultimately derailed by a culmination poor transfers decisions - which we can't really blame on McKenna (hopefully our recruitment will be sorted out and no future manager will be identifying targets).