The Torah of the Avos is the same Torah as today. Part of the answer may lie in the fact that the Avos had a very unique and perceptive ability/intellect (far beyond ours) which could “see” or “experience” different realities.
So, again, the question is put to you: Ya’akov Avinu could “see” or “experience” different realities in the Torah with his perceptive abilities that are far beyond ours and yet but couldn’t read the pasuk that said that Yosef was alive and well in Egypt?
The Wolf