I think the basis for your answer is in the opening statement." developed by a voluntary effort". Your talented councillor is apparently not receiving payment for their ongoing management of the web site at the moment. It would need to be ascertained whether the person involved was happy to expand their workload as required still on a voluntary basis. Any incidental costs, (ongoing domain and hosting costs) already being met by the council? If so then it would be a decision made by council as to what costs incurred could should or would be passed onto the NDP Group. As is usual, the NDP would be produced under the stewardship of the PC anyway and they would need to consider their obligation to supporting ( and funding) community projects such as this. So it is best to keep the website work as a voluntary basis as this avoids any complications of conflicts of interest etc. with a clear and transparent decision making process as to content so that the site is always under control of the PC and not one person ( or company)
Unfortunately having a talented councillor doing it in itself is not a problem but implications of this route need to be considered ( i.e retirement of councillor, illness, etc etc. ) and contingencies put in place.