I’m not sure it’s the replacement for the Muddy Mary- despite the name the Muddy’s supposed to be an intermediate whereas the Magic is more loose/wet. The Muddy’s still on the website as a current model.
But then Schwalbe like to say that all their tyres are good at everything so it’s kind of hard to tell what’s for what without actually using them sometimes. As far as I can tell, the Muddy Mary is mostly designed to have all its knobs fall off the first time you go round a corner, except for the hard compound version which deals with that by making it hard to go round corners