That's interesting; if you're doing human in the loop, I would have thought it'd be easier to just do voice swapping. Or did the technology not quite line up?
But the main reason is, there's a lot of brand imagery on the line with these interactions, someone putting on a voice, or using a voice changer could make a mistake. Disney instead have a conversation tree with pre-recorded voice lines that a remote operator can control. Much harder to mess up