Yes, I think they are Tibetans. The traditional definition of Tibet is Ü-Tsang, Kham and Amdo. These are the three traditional provinces of Tibet.
For example, Amdo is mainly the Qinghai and Gansu provinces of China. That's where His Holiness the Dalai Lama was born, which is outside of the Tibet Autonomous Region. My father comes from Kham, which is presently in Sichuan province. To say that Tibet is only the Tibet Autonomous Region is to say that the Dalai Lama is not Tibetan or that my father was not a Tibetan. We all are Tibetans.
What we seek is genuine autonomy and administrative authority over Tibetan people, because they have the same language, the same culture, the same spirituality and even the same terrain. The territory is all a mountainous region; hence, having one administrative structure is more efficient and capable.
Yes, the Chinese government sometimes says, “Oh, what Tibetans are asking for is one fourth of China. This is unreasonable. The Dalai Lama is unreasonable.” No, we are not unreasonable because, historically, that's where Tibetans have lived, and that's where Tibetans are living now. The Dalai Lama is a Tibetan. My late father also was a Tibetan. That's the Tibetan Plateau.