[Update] Bungie has since spoken out regarding the departure of O'Donnell, reaffirming the fact that Destiny is still on track and "close to shipping."
Bungie COO Pete Parsons confirmed to Eurogamer that Marty's music will very much be in Destiny and will satisfy fans, telling the outlet:
I think the Bungie fanbase is going to look forward to hearing Marty's music, Mike Salvatori's music, C. Paul's music and Paul McCartney's music in the game. That's going to be exciting for people. It's going to be a great, fantastic experience.
I believe people will be transported not just by the activities and the stories within the Destiny universe but by the sights and the wonderful sounds and music. We have a fantastic team. We're pretty close to shipping. There's a lot of polish left to do, lots of tweaking and tuning, but a lot is already complete.
Destiny is set for release on September 9th for Xbox 360, Xbox One, PlayStation 3, and PS4.
According to O'Donnell, he was sacked "without cause." He explained on Twitter:
For more than a decade, Marty O'Donnell filled our worlds with unforgettable sounds and soundtracks, and left an indelible mark on our fans. Today, as friends, we say goodbye. We know that wherever his journey takes him, he will always have a bright and hopeful future. We wish him luck in all his future endeavors.
I for one hope the folks over at 343 Industries are banging on his door right now. The fanboy in me would love for him to return to the Halo franchise.