Again, it was not meant to be a comparison.
What?! OK, now you've definitly lost me, you think that soviet national identity was defined solely by totalitarianism? Not socialism, not being a worker's state, not having the soviets as it's de jure main decision bodies and not being the successor to the historical russian empire, but totalitarianism? You think that having gulags is an absolute requirement for a country to be called the "Soviet Union"? That's far too specific to be a requirement for nationhood.
Let's imagine Kosygin managed to consolidate power in the 60s and started introducing liberal reforms. By the 70s, the Prague Spring would occur, Kosygin wouldn't crush it, and liberal ideas would spread even further throughout the Eastern Bloc. Under these circunstances, it should be possible for a full democracy to be in place by the 1980s. This democracy would present itself as the "Union of Soviet Socialist Republics" and that's also the name the whole world would know it by. It would have the same exact borders of OTL's Soviet Union, it would also share it's symbols and it's constitutional commitment to the ideology of socialism. It could even be ruled as a "Soviet Democracy", like it was originally supposed to be according to it's lenninist constitution. I just don't see how that country could not be considered to be the soviet union!
Granted, it'd be very different from OTL's Soviet Union, but I don't see how that means it would stop be the same country. A change in political regime doesn't strip a country of its nationhood. I recognize that if they removed Socialism from it's place as the sate's official ideology, you would have a point, since socialism was obviously integral to soviet national identity, but you definitly can't say the same things for gulags and the KGB.