I would have probably said something to a CM nearby. That bothers me, as a mother with two preschoolers. Yikes.
Yes, I think this kind of thing needs to be brought to Disney's attention, via CMs. Nothing will change if people who notice it do not challenge it. I am sure it wasn't deliberate on Disney's part, but they probably do not put a lot of thought into that kind of thing. If they know that it is important to guests I think they would make an effort to eliminate unhappy guests by monitoring it. They probably do not even have a policy on music played near attractions regarding lyrics, but maybe if enough guests make their feelings know, a policy can be put in place and implemented to ensure positive guest experience.