Indeed. I'm not sure what the industry could do in this case. It would be up to the theatre owner to contact the musicians - which they can choose not to do. I imagine the composed would get a cut if electronic score has to be licensed for public performance (it would be slightly strange for this not to be the case).
It might be hard to find musicians later though; I'm not sure many musicians make a full time career out of this sort of work, but it might be just be the last straw - god knows I've seen enough string quartets busking these days and that can't be much of a money spinner.
All in all, it sucks to be a musician these days - composing, recording or performing seems to be a talent which is rather unappreciated (to the extent that anybody is willing to pay for what a musician produces).