Disney's decision to debut 'Mulan' on Disney Plus for $30 could mean big changes for movie theaters, but the economics of high-price digital releases are daunting

· Disney announced last week that it would release "Mulan" on Disney Plus for an additional $30 premium fee.
· Paul Dergarabedian, the Comscore senior media analyst, said that "nothing is off the table" now in terms of other movies heading to premium video-on-demand services. 
· The media research firm Lightshed Partners...