That is basically true, but let me explain exactly what that means. The totalitarian school of historiography really focused on the state, the party and the leaders of the Soviet Union. The totalitarian model, therefore, failed to actually study huge amounts of the Soviet Union because it was operating under the assumption that the totalitarian nature of the system was, well, totalitarian - or in other words infiltrated all aspects of life. The reason this school no longer has much steam has a lot to do with changes in the study of history - an emphasis on the study of everyday life, culture, and society over the past say, 30-40 years. Although the opening of the archives after the Soviet Union disintegrated was an important part of deepening our understanding of the Soviet Union, the totalitarian school was challenged much earlier.

It's important to realize here that a rejection of the totalitarian model is NOT necessarily a rejection of the idea that the Soviet Union was authoritarian. It is a historiographical and theoretical challenge. The group of historians that first challenged the totalitarian model - called the revisionists - said "Hey, wait a second now, there are millions and millions of people living out their lives in the Soviet Union and this model essentially grants them no agency. What are people actually DOING?" Certainly they are doing things within a country that is still ruled by a single party and that was varying levels of repressive throughout its history. There certainly was a political element, let's not kid ourselves either, but the the conflict between the totalitarian and revisionist schools was also quite generational and I think reflected broader trends in history in general and not just disagreements over the Soviet Union itself. The Cold War certainly amplified the political importance of conflict, but in hindsight I see it mainly as a historiographical shift.

Any grad student studying the Soviet Union is going to read their share of works from the totalitarian school because it is an important part of the historiography, but it is by now mostly historiographical artifact in my opinion. Also, note that many fields have shifted in a similar fashion such that older works are often considered somewhat outdated and that this is not just to do with the "facts" in these books (although they are often challenged on that front too in the Soviet context, but mainly because of the subsequent opening of the Soviet archives in the 1990s), but their theoretical and methodological approaches. On that note, we are well into the realm of what is usually called "postrevisionist" historiography in the study of the Soviet Union now.