If they add more Sound based attacks that deal damage this would be nice. As it is now only Bug Buzz, Chatter, Echoed Voice, Hyper Voice, Relic Song, Round, Snarl, Snore, and Uproar would gain a boost. Before Gen 5 there really weren't that many damaging Sound based attacks.
Some issued would come in with what would be where. Chatter and Relic Song are struck through because of exclusiveness. I don't see them giving Chatter out anymore due to the reason of its banning from competitive play. Bug Buzz and Snarl are exclusive to Bugs and Dark Types/Dog like Pokemon.
Course Whismur Line would come in and be all STFU against any Pokemon relying on that kinda ability. I can see Sound Based move nullifying items appearing for the same reason.