So does everyone agree that kundalini awakening is necessary for enlightenment?
The view that kundalini awakening is necessary for enlightenment is held in the diverse literature of Kashmir Shaivism and in other Hindu Tantric literature. It is found in the literature of the Hatha Yogis and the Nath Sampradaya. You will find similar views in many Buddhist Tantric works. In addition this view is held by recent spiritual figures such as Shri Ramakrishna, Swami Sivananda, Paramahamsa Yogananda and Swami Vivekananda and of course by contemporary kundalini yogins themselves.
Nevertheless there are some dissenters from this view. These include Sri Chinmoy, Da Free John and Gurdjieff. Dissent can take a number of different forms. For Gurjieff kundalini is associated only with a binding force that leads us to be more attached to the world. Such a view of kundalini is not entirely inaccurate but only reflects the functioning of kundalini in the lower energy centers. For Sri Chinmoy kundalini is an amplifying function that may make an individual more powerful but not more enlightened. From my perspective this also only addresses the impact of kundalini while it operates in the lower energy centers.
Da Free John (born Franklin Jones, a. k. a. Da Love Ananda) has a much more fundamental criticism of kundalini. As far as I understand his position, for him enlightenment cannot be the result of an experience; it is a cognitive transformation. Kundalini may evoke a wide variety of experiences but these are not in and of themselves enlightening. This is an interesting perspective but it seems to assume that the raising of kundalini is an experience in which an ego-consciousness experiences a separate object known as kundalini. Again, this view is consistent with the experience of kundalini in the lower energy centers in which the ego is detached from the movement of kundalini and kundalini experiences are precieved as separate from oneself. However, I would argue that as kundalini rises the ego-consciousness becomes infused in a more fundamental consciousness of cit-shakti-kundalini and this experience does in fact produce a fundamental cognitive change.
Finally, there are many other spiritual practices, such as Zen, Vipassana meditation that consider kundalini irrelevant. Some practitioners or even teachers of these paths, such as Jiyu Kennet, may have kundalini experiences but generally kundalini is not a pivotal part of these paths.