Regardless, the fact remains that the Texas state governor has announced a ban on mask mandates, and the local school districts in all of the major urban areas are directly disobeying. They are daring the state government to take them to court. It will be very difficult for the state to engage in legal battles against all of the major cities, so I suspect it won't go anywhere.
As lh320 pointed out, from a scientific experimental standpoint, we're about to gather some interesting and relevant data, since we'll have very large test groups as well as very large control groups. By December, we're definitely going to know how much, or how little, masks help with reduction in infection of spread, among school children.