I'm going to say this as someone who has gone to London to see a play or two or three , people don't dress up anymore to the theatre. But they don't dress down either like a pair of chavs either or the flasher on the corner . (Flasher Mac).
Also would you consider watching a musical as theatre ?. I wouldn't.
I went to see Ralph Fiennes and Tobias M. (Prince Philip The Crown) in plays I wouldn't say theatre.
I really don't see Hinch & Inch taking in Ibsen , Chekhov or a modern interpretation of Shakespeare..
My monies on them going to a musical and maybe I'm a snob .