Your claim is laid out nicely. While Elon is certainly motivated by science, logistics, and rationality, there's definitely something "religious" about him striving to expand human life into the future.
Musk is highly intelligent, capable, and perhaps plagued with luck. Nietzsche explained Christianity as a religion of pity, one that denied people with exceptional capabilities to rise above (Elon). So how could Elon possibly fit into a traditional religious category? Well, he seems to be outside of it, in some sense—with his exceptional intellect and vision.
However, he certainly seems to be acting out the spirit of a hero, or a savior, by attempting to extend humanity forward in Mars. So while Elon does not "identify" with religion, there's deep truth for everyone in what he's pursuing.