>>20618550As an Altaria fan, I'm so torn.
Boomburst actually does make some sense due to Altaria's singing/humming theme and wide array of sound moves. Plus GameFreak has given plenty of Megas new toys that mesh perfectly with their ability and type, like Mega Heracross's Skill Link moves, the Pulses for Mega Blastoise, and Mega Ampharos and Lopunny getting powerful new STABs. The move is also in Altaria's breeding pool thanks to Noivern, Chatot, and Swellow. It wouldn't be too far outside the realm of possibility.
On the other hand, GF can't always into logic or flavor. Also, it really would be pretty nightmarish in battle. Especially in VGC provided you had a Soundproof partner. I'd kinda like to see it happen, but I'm scared of the potential fallout. I'm also not expecting anything to come of it.