For trading NFP I use EURUSD because it is the most liquid pair if it is what you are talking about.
However, there is no way to know in advance if the news effect will be either positive or negative for a specific pair nor asset.
These kind of things are really easy to verify: Check the past NFP releases of the 6 months and see if that happened. These kind of statements are very easy to dismantle just by looking at the past data.
Look a few:
https://www.investing.com/economic-c...m-payrolls-227