I'd say so .. anyway compress keys and uncompressed keys carry the same information and can be computed from eachother
Though the compressed version obviously needs less space
For the gateway stuff it becomes a problem, because someone could import their uncompressed private key from bitcoin, which would get turned into a compressed bitshares pub-key, so when bitAssets are sent to the gateway, the bitshares pub-key of the sender is looked up, which maps to a different bitcoin address than the one the user has in their wallet because it's now compressed instead of uncompressed.
This would mean bitcoins would never arrive in the users wallet, they'd need to add the compressed private key in order to get their funds.