Absolutely. I witnessed a Pair of blue discus (Not sure what strain exactly) in a tank with gar fish and a bunch of other Misc Fish. this was at Big Als in Mississauga, ON. If they will breed there believe me , they will breed anywhere lol.
Essentially , the fry were mostly eaten and I havn't been back in about 1 week and management did not seem to care all that much about caring for them so likely all dead now.
but yeah , they will breed in a community tank ,however expect them to become chow.