What do we discover about how life in Gilead changed after Offred`s narrative ends?

We can surmise that things have improved. Although the lecture lends a sense of authenticity to Offred's account, it nevertheless is speculative about the details. THis is known as speculative fiction. The speaker questions the oral tradition in the place of hardened factual evidence. The speaker's theme and tone has a sense of disbelief that Offred's account is completely true. THe sense of shock adds credence to that the role of women in society has evolved.

"In the epilogue, Atwood inverts Gilead, overthrowing the terrible world that she created. In opposition to the Gilead’s white, male-dominated patriarchy, in the new world the whites are the subjects of study, not the scholars and rulers. Professors have names like Johnny Running Dog and Maryann Crescent Moon, which suggests that Native Americans dominate the academy. The great universities are in Nunavit, in northern Canada, and the map of the world, we are assured, has been remade. Once, white people studied the Third World; now the chair of the conference announces a speech from Professor Gopal Chatterjee, from the Department of Western Philosophy at the University of Baroda, India."