Satoshi Nakamoto is a mathematician. I am a physicist. I had  a mathematics professor that could be compared with Satoshi Nakamoto. When bitcoin was invented in 2009, the quantum adventure was at its beginnings.

I made my PhD thesis on quantum wells (in 2000), in 2009 what was in my PhD thesis was learned in the QM in the 2nd year of faculty.  When bitcoin was invented no one could say that Quantum Computers will be invented in 10 years.

Thus, Satoshi Nakamoto did not think that quantum computers will exist when he invented the bitcoin.