It means that when larger groups of people were organized by a new ruler that integrated individual villages of the Yayoi period, changes occurred in the ceremonial style from one of each community to one of a man with absolute power, leading to burial of dotaku that had been used in each village.
つまり、弥生時代の個々の村落を統合する新しい支配者が現れる等して人々がより大きな集団を構成する際に、それまでのそれぞれの共同体の祭儀から専制的権力者の祭儀への変化が起き、各々の村落で使われていた銅鐸を埋納したというものである。