Not likely, but we do not know for sure. For sure, his teachings on overcoming suffering in this life suggests he didn’t. Also, he did not believe in an afterlife for the self you feel today. That is clear with his teachings on non-self. His focus was on overcoming suffering in this life, not the next.
In ancient India, Mount Meru was widely understood as the cosmic mountain at the center of the universe, with realms of gods above and lower realms below. This worldview included six realms of existence: gods, demigods or asuras, humans, animals, hungry ghosts, and hell beings. These ideas shaped ancient India and influenced traditions such as Hinduism, Jainism, Buddhism, and later Sikhism. Even today, some believers take these realms literally, while others treat them more symbolically.
The Buddha incorporated local cosmology as teaching tools, not as the center of his message. This fits well with the broader Buddhist shift away from a permanent self. What continues is not the self, but more like a lingering essence shaped by karma. Not a soul in the self-identity sense, but a continuity of non-self. Non-self is key to overcoming suffering in this life. In this framework, local beliefs were not the focus.
So the cautious answer is this: the Buddha taught within a worldview that included Mount Meru and the six realms, but his enduring message does not depend on those ideas being literally true. Buddhism allows you to honor the story, learn from it, and still ask hard questions about what should be treated as belief, symbolism, and truth.