There is no proper abandonware. Abandonware is a made up term. It's piracy, plane and simple.
Hence why I said it's fine from a moral angle, not from a legal one. It's not a valid legal construct, but it is a moral one.
I agree that a differentiation between piracy of games still sold (whether physically or in bits and bytes) and games not currently sold is useful. It will not be legally accepted for a long time, but you can't expect laws to be up to date with something that changes as fast as technology. Were we lead, the law will follow.
Abandonware however should be abandoned (pardon the pun) due to its association with the bad kind of piracy and since many old games have not really been abandoned but rather put on hold.
Here are my suggestions for a replacement term for software currently not for sale. Feel free to come up with your own.
Unavailableware, unaware, voidware, lostware, hiberware, cryoware, coldware, noware.