There’s no direct canon confirmation, but it seems quite plausible that it was, in fact, the Bynars who provided the technological leaps necessary for the Enterprise computer to generate Moriarty and other proto-sentient characters. Riker and Picard both comment on the realism and perception of Minuet, created by the Bynars on the holodeck after their upgrades.

And there is a direct canon line from Moriarty through to the EMH and later sentient holograms via Lt. Barclay.