While I think what you're suggesting is problematic, I agree with your premise.
Even if it were as simple as letting people run around in Jedi capes and having cast interact differently with those people who have chosen to be "in character" it would be a huge step closer to what they claimed they were going to offer.
But frankly, aliens and cast that aren't in pristine looking uniform-costumes would also be a huge step in that direction.
I can understand there may be some crowd-control issues but it isn't like WDW hasn't pulled this sort of thing off before.
I mean man, where's a talking, moving trash can when you need one?
Even something like a re-themed Mr. Potato head or Pirates of the Caribbean parrot "barker" or a droid like the ones you see in line for Star Tours would work - and that's all proven tech.
Heck, in our warehouse, my employer has automated robots that roll across the floor using technology similar to the trackless ride system and those interact with people all day long. They stop and start constantly to make sure they're not running over anyone and they are large industrial things carrying literally a ton or more of weight and they've been at it for more than a decade. (and it isn't like Disney would need to have something like this moving around people - have them "servicing" some of those space craft behind barriers in an endless loop to make 'em look less like set pieces and more like actual working vehicles).
It isn't like any of this stuff is new or exotic or even crazy-expensive tech and when the theme is a "droid" to begin with, you don't have to do a ton to spice it up. I mean, those Star Wars droids in the queue checking luggage were originally birds from America Sings like the ones in Splash mountain but without the costume, right?
Bet they've got a closet full of animatronics left over from the Mickey Mouse Review they could just peel the skin right off of and be ready to go with a few LEDs and extra plastic/metal pieces bolted on.