The theories which are explored in the Washington Post article (around the idea that someone Wuhan Institute of Virology might have been accidentally infected with the virus while studying bats) are completely different to the claim the it's an engineered bio-weapon that came from those labs.

(To be clear, Tom Cotton himself says the bio-weapon thing was just a hypothesis[1].)

[1] https://twitter.com/SenTomCotton/status/1229202134048133126