She didn't mention what those particular strings are. Most of the federal rules are regarding spending Title I funds and special education funds which are the only federal funding contributions. Another lesser-known rule is that the federal government reimburses the cost of the education for government employees that attend local schools. When I was in the military, I completed a form every year that was turned into my kid's school that I was military and assigned to a facility in the local area. I did this in Rhode Island, Virginia, and Florida. When I worked for the US government (DoD) I did the same in Kentucky.
There is no agenda. This has been that way for decades.
Most people confuse funding issues with things like Common Core standards being promoted by the Education department back in early 200O, but it was only offered as additional funding to implement those standards. If the state chose not to use them, there was no penalty. Many states refused the funds and lost nothing because they had no costs to implement them.