Yes, all is Brahman, including the maya that is the world it manifests. But unlike its maya, which comes and goes, Brahman does not come and go. One metaphor is gold and the chain from which is is fashioned. Whether fashioned into chain or not, gold always remains as gold. Gold has not become a chain. Nothing has been added. Only the formless has become form:
Brahman and Maya
Brahman has “become” the world through maya
Brahman is...absolutely real and formless. But then, there must be something with
that Brahman to be able to ‘become’ this world of forms. This power is called maya.
Maya is there because this is how Brahman is. We don’t ask, “Why is there
maya?" because we don’t say that there is maya; We say that there is only Brahman. Brahman ‘plus something’ doesn’t exist at
all. .....any ‘plus’ is dependent upon Brahman for its existence and is therefore maya.
The world is Brahman. If Brahman is limitless consciousness, without any particular form, then how could it become this world of
forms? It did not. Consciousness continues to be, without any change. The gold has not become a chain. Only if it becomes a chain do I have to answer the question, “How did it become a chain?” Gold continues to be gold. Once you understand that clearly, then we can say Brahman has “become” the world through maya.
Swami Dayananda Saraswati
http://www.discovervedanta.com/downloads/articles/brahman-and-maya.pdf
When we see the Universe (ie 'the gold chain) through the conceptual filters of Time, Space, and Causation, we see it as a material world that is changing all the time and composed of various 'parts'. But when we remove those filters, we see the Universe as it actually is: as The Changeless Absolute (ie; pure gold), because change takes place only in Time and Space.