Okay:

Disney did not "revive" the concept of live theater and, for that matter, what it does is irrelevant to live theater except for one thing: too many people think Beauty and the Beast is theater, rather than what it really is, namely a commercialized cartoon. Disney has created an appetite for spectacle and the belief that musical theater is some light piece of froth with an intended demographic of 10 year olds. Disney has brought nothing new to the stage, nothing remotely inventive with, perhaps, the exception of the Lion King, which was an interpretation of the cartoon, rather than a literal staging of it. However, even that interpretation wasn't original -- many shows before it used similar techniques for realizing animals, e.g. the horses in Equus, and succeeded as theater in spite of the music. Music works in a very specific way in a musical -- the score is not a collection of songs, but a participant in the plot, advancing the story, rather than merely interrupting it. 19th century burlesque adapted popular music to the stage, too, but it wasn't musical theater, at least not in the sense that the term is used to define that particular art form which evolved in the U.S. in the 20th century. Disney's other Broadway efforts aren't theater -- they're theme park entertainments, no different than "On Ice" diversions.

Disney doesn't employ theater people world-wide. Quality English-speaking professional theater is found in just a few venues: Broadway and London, regional theaters, touring companies and a few resident productions in major cities.

Not theater. I have no interest in Disney theme parks or related undertakings as I don't have children. I do, however, have a passion for theater, and have had it all my life. Disney's contribution to live performance merits little more than a footnote in theater history.