It will probably depend on whether anyone's created a bug report on it in the Bug Reports section I'd say (that's the best way of letting Frontier know there's an issue).
I don't think, that a bug report is needed for this "bug".
They know, that there is no sound coming from the billboards and they told us before the update and in the update information, that sound will be added in a future patch. (But they didn't tell us, when this patch will be).