Yes, but then the buyer knows they're only getting Steem OR Hive.
If I know the snapshot was yesterday, and you assume its tomorrow, I can sell you postfork Steem (no hive drop), as prefork Steem. You buy expecting to get both after the fork, and get disappointed since its not steem you were holding before the snapshot. 
Happily this won't be an issue as they've announced the snapshot and fork will be simultaneous, which is definitely best :)