They have psykers and astropaths, but they don't really embrace them, although they need them to survive. Lorewise they are religious, but that's not expressed the same way as spiritualism, it's rather a result and a source of their collectivism. I don't think Spiritualist is a thing for Imperium (if we consider spiritualism = telepathy and connection to the universe and materialism = robots and exploiting all the resources they can).
