Presumably destroyed. Maybe a few could be in DiC or Sony's archives. But for the former, WildBrain owns them now. Not sure where DiC archives are, either Burbank or WildBrain's headquarters in Toronto. But then again, neither had the RGB pilot and by luck Robert Barbieri stumbled onto the pilot's film reel.
However, I'm pretty sure to save on storage costs and space, once film copies of episodes were transferred to broadcast beta tapes, the originals were destroyed. The tapes I think are the most original source left.
edit: Robert mentioned it a few times:
https://www.facebook.com/groups/3214495 ... 0013504643 "speaking of Film copies, I can officially confirm they just dont exist. DIC was cheap after moving many times in the 80s and decided to lose some dead weight and save storage money and film copies of the episodes were discarded once they were transferred to supermax broadcast beta tapes."
https://www.youtube.com/watch?v=fQL4CFu ... G9Jat2F2Al "As the Director of this pilot told me, DiC had moved their storage so many times, at one point they decided to cost cut and get rid of some clutter basically. They had the U-Matic broadcast tapes so the heavy film reels which were also a potential fire hazard as learned by the fire at the Universal Studios lot where the BTTF2 2015 set got destroyed. DiC discarded their expensive liability of film stock."