Kusari has stated on multiple accounts that they have no desire to go out of their way to target 'Trade Vessels' or deal any significant damage to civilian infrastructure unless it can't be helped. They have their designated Military targets and will rain down fire on those specifically to attempt to cripple Gallia in the long run, shipyards are the most obvious. If Gallic Corporations move to assist the Defence forces and Enclave directly however, I can see them being targetted, an exception to their doctrine in this war.
However, if Kusari so desires, they could change this tune if they wanted. That said, Story has yet to hear as such. So for now, it is what it is.
When contending with a monster, you'd be wise to give the devil his due.