Given that the L-Mount Alliance troika indicated it might expand to additional manufacturers, DCLife has suspicions that OM Digital, the holder of the Olympus camera brand, may be a prospect.
It is true that a Sigma executive recently mused about the expectation that the alliance could expand. It is also true that OM Digital has more strategic flexibility, now that it is spun off from Olympus. But the philosophical limit to the MFT mount does not appear to have originated from corporate headquarters, but rather the camera division itself, as it carved out a defensible market niche.
OM Digital doesn’t have to change mounts to be part of the L-Mount Alliance. An interesting product from OM Digital (or Panasonic) would be an adapter/speed booster that could take L-mount lenses and cause them to be up to two stops faster on MFT rigs, simultaneously solving the crop issue. Taking a lens like the Sigma 500mm f/4 and making it a 500mm f/2 would be something unavailable on full frame cameras and make the MFT family more relevant to the low-light photography.