The most plausible rationale for this kind of broad and immediate cancellation of contracts is to indirectly shut down the function of these agencies.
1: https://www.theatlantic.com/science/archive/2024/07/noaa-pro...
2: https://www.cnn.com/2017/10/14/politics/noaa-nominee-accuwea...
3: https://www.pbs.org/newshour/politics/fact-checking-what-pro...
> The document describes NOAA as a primary component “of the climate change alarm industry” and said it “should be broken up and downsized.”