CSX, like many companies, will observe the holiday on Monday July 5th.
Nothing running out of Readville, Middleboro, or Walpole Sunday.
Only jobs that I am aware of that will run on Monday night are the "feeder" type jobs B725 (Framingham to Attleboro) B726 (Middleboro to Attleboro) and B731 (Readville to Framingham).