I've read most of Gould's books and most of the Nature articles from which they are taken. I've never seen anything like that. Do you have a source that isn't a cobbled together quote taken out of context?
Gould's "definitive" response to the question of stasis vs "upward change" is found in one of his last books, Full House. Evolution permits stasis when no change is required for survival. Thus, bacteria comprise the bulk of live, by weight. But mutations are constantly providing new kinds of individuals, and some of them survive (which doesn't mean the unchanged individuals do not also survive).