I usually don't like tooting my own horn, but I'm speaking as someone with 18 years of experience in the financial aspects of school food service. I was one of those middle-management bean counters working for large districts around the Northeast.
This will absolutely wreck school food service in many schools. Even before Trump ever set foot in the White House, school food service was often the red-headed stepchild of many school districts that operated on shoestring budgets and were almost always the first to get cuts whenever the school district needed to tighten its belt. These food aid programs in many districts were the only things keeping these programs anything resembling solvent in the first place. I cannot emphasize enough how reliant that our NSLP programs are on this funding.
At least right now, schools are still required to continue serving lunch under federal law. Of course, I'm sure that this will be rectified once Trump realizes that the NSLP exists and decides to cut that too because the program is using food grown in Canada to feed gay kids or something. What this is going to lead to is that NSLP programs are going to be cut to federally required minimums. And without these grants to pay for it, other school services will have to be cut. Teachers will have to be laid off. Other programs will have to be cut in order to pay for school food service. All of this and students will end up receiving less nutritious meals than they received before anyway. Again, that's until Trump realizes the program even exists and just shuts it down entirely.
You know how we occasionally see those articles about students carrying huge lunch debts at school? Think that, except worse. And everywhere.