Initially it is not a problem in the way the community fees are being allocated, but longer term it could be and agree now is the time to acknowledge in legal minutes when expenditure is incurred on the private road the appropriate costs will be allocated appropriately to the liability as within the deeds and the appropriate properties.
Formally addressing this via an agenda item at the next meeting is perhaps the best approach.
As when buying any house, we also requested clarification on the responsiblity for certain things and for the purchase in Spain this included future liability for road expenditure. We specifically selected a plot which was on a public road, rather than private road so can understand your concerns around giving clarity to all on this matter at the beginning of setting up the community.
Equally, we would like to assure any readers/fellow owners our desire is to have a well kept and managed community/development, irrespective of the phase a property is located on.