I'm happy to announce that, on Augst 4th, BSA posted a note on their blog stating that that decision has been reversed, Here's their announcement:
In early June, we reported that the Bugling merit badge was to be discontinued and its requirements merged into Music merit badge.
That's no longer the case. Responding to concerns from hundreds of Scouters, the BSA's Youth Development team has decided to reinstate Bugling as a separate merit badge.
Oddly enough, this means that Bugling will never have officially been part of Music merit badge, because the changes were never reflected in a Boy Scout Requirements book.
Bugling and Music will continue to share a merit badge pamphlet. Requirements and information for both of the badges will be contained within that single booklet.