The undertakers involved in this will have made sure the deceased has arrived for the burial in good time and not have the usual concern for that trip from the mortuary to the customary place of cremation or burial. This will have happened long before the ceremony and it could be that all the deceased for that day could be taken together well in advance and at a time convenient against traffic jams, again an efficiency that could be significant.
Also the ceremonial travail, slowly as might happen from the mortuary or the relatives abode to the cemetery will be a thing of the past and will be replaced in effect by the slow transit of the vessel from the place of the ceremony to the open sea for delivery there.
I have seen a documentary from the USA where the value of convenient land or space in existing cemeteries is such that the coffins are interred standing up. This situation will, must only get worse and how poorly this compares with the image the freedom of the seas will provide.