The doctrine preached in “The Life Span of the Buddha” chapter is not suitable for the capacity of those in the second 500-year period of the Age of the Semblance Dharma, not to speak of the first 500-year period. Those in the Age of the True Dharma were not ready for the theoretical section of the Lotus Sūtra, not to speak of the essential section. In the Latter Age of Degeneration, the pre-Lotus sūtras and the teaching of the theoretical section of the Lotus Sūtra, which were suitable in the Ages of the True Dharma and the Semblance Dharma, no longer enabled the people to shed delusions of life and death and attain Buddhahood. The 16th chapter of the essential section preaches the single, indispensable teaching for extinguishing delusions and attaining Buddhahood.

Looking at it this way, I am sure that in providing guidance the Buddha never acts impartially; He just preaches the dharma suitable to the time and capacity of the people.

Sandai Hiho Honjo-ji, The Transmission of the Three Great Secret Dharmas, Writings of Nichiren Shōnin, Doctrine 2, Page 288