I've been following his career for a while, and he isn't in the 'alt-right' at all. He professes absolutely no inklings to white nationalism, and in almost every time he talks about politics he harshly criticises Trump. He (I think wrongheadedly) criticises all religions as a new atheist, and has stated that he sees a clear difference between criticising the doctrine of Islam and Individual muslims. He 'platforms' all sorts of people on his podcast, whether he agrees or disagrees with them; sometimes its fun to listen to a debate you know?

The Waking Up app and book are based on his experiences studying meditation with all sorts of teachers, primarily Tibetan, and taking methods of meditation that he has personally found helpful and making them more accessible to a secular audience. I personally disagree with him on many things, but that doesn't mean I cannot benefit from his style of teaching meditation.

As someone that has been down the alt-right rabbit hole and came out the other side, trust me he isn't even near alt-right, and if people benefit from his meditations, why shouldn't they?