"Your quote shows that the AstraZeneca vaccine loses effectiveness over time. However, the chance of an unvaccinated person passing on the virus is 67%, which is significantly higher than the 58% for a person who received the Pfizer vaccine."

The word "significantly" has a specific statistical meaning. The paper discussed on the Nature article implies it is not a statistically significant difference between 67% and 58% (likely accounting for covariance and measurement error).

Unless you have a different source showing there is statistical significance between those two results?