He does not put it that way explicitly, but what he is saying is that he hopes we do not gain knowledge that he would would regard as diminishing the likelihood

He does not put it that way explicitly, but what he is saying is that he hopes we do not gain knowledge that he would would regard as diminishing the likelihood of his hope for humanity being realized. Note that gaining that knowledge would not actually change humanity's chances for colonizing the galaxy; it would only make that probability more clear to Bostrom.