Honmon Butsuryu Shu [HBS] makes the same claim, "in a Buddhaless world"

"The fact is that the Buddha of the Lotus Sutra has a life span that is immeasurable; he abides constantly in the world without ever entering extinction. But the Zen school, as we have seen, regards the Buddha as already having entered extinction, and therefore it may be said to embrace the view of the non-Buddhists that things cease to exist. This is an erroneous view that contradicts the golden words of the Buddha, “These phenomena are part of an abiding Law, [and] the characteristics of the world are constantly abiding.”