Okay. I'll bite.
I have not heard those specific call outs on all the times I have ridden GoG, but I am strongly under the impression that the question IS intended to elicit a response from the riders. Riders often call a response that makes everyone laugh, and that = one more way the ride varies from ride to ride.
Also, whenever we ride the ride, we DO get into the music. When it comes to coasters, shouting is to be expected. I've never been on ITtbaB that the audience did not react out loud to the spiders, etc. The audience is expected to participate during a number of the WDW shows. Like to ooh! whenever the owl flies by and to laugh at corny bird jokes.
IMO, it is a bit odd to say it is okay to verbally participate on some attractions/shows, but not to sing along/verbally participate on other attractions.
Mind, over-the-top loud and nonstop talking about non-ride stuff (while ignoring the ride) is annoying, but I don't quite understand the everyone must remain silent expectation either. I'm happy whenever a ride elicits a cheer, smile, clapping, etc.
Part of the fun of a theme park is the collective reaction to the stimulus that surrounds us. When a joke is told, I WANT to laugh along with strangers. When a child sings along on Small World, I smile. If people laugh a little too loud, so be it.