It might become more relevant when we get the Eastern Front packs or for very early war scenarios but units at this scale (Coy) were hardly ever without coms to the guns. Even if the lines got severed they still had radios to fall back on.
In good weather they had the Air OP's that could conduct the shoots.
If we are going to make it more realistic I would suggest just a very small random chance for lost coms. This just needs to be a random roll whenever you place a bombard marker, modified by the units current organisation maybe?
For the rare occasions when there was no coms with the guns, it could be for many different reasons, cut lines just being a small percentage of that. It could be that both OP parties had been killed, radios destroyed, broken, the FDC destroyed or the guns under counter battery fire as just a few examples. The guns being under counter battery fire is modelled in the game of course, with their suppression.
Its great what you have done, and would be awesome for a game at section level, but with the numerous ways that fire can be directed at the Coy and Bn level I don't think it needs to be modelled that accurately.
What could be looked at though is the intel on the enemy arty batteries. With reference from the reading I have been doing, I think they should be much easier to spot once they have fired, from much greater distances and they should stay spotted for longer to allow the AI to continue to counter battery fire on them during attacks, rather than just a 5 min stonk.
In good weather any moving, or in the open, Arty unit should be spotted to simulate the extensive use of Air OP's.