^It's a valid concern, but it might be worth noting that unlike Susan Stroman, Matthew Warchus already has 2 feature film directing credits under his belt. Whether those 2 particular feature films are encouraging examples of his skill is a different question, but in any case, it's something.
I also just think it's a different situation. Stroman is an old-fashioned director by nature; her style harkens back to a time when it was more traditional to do stage-y movie-musicals. Plus, she was dealing with a property that was a monster hit, with its original stars. I can see why there was an inclination to copy-paste the stage version.
Warchus is a traditionalist in some ways, but his work has a more contemporary feel. And he has a flair for visuals which I think will serve him well for an adaptation like this. Not to mention, he has the benefit hindsight. He's making this film at a time when stage-to-screen adaptations are experiencing a resurgence in popularity, and recent history has clearly shown that making significant adjustments to suit the new medium is beneficial.