Everyone here has short memories. This is the annual intimidation letter before summer starts.
They are afraid they don't have enough pilots to fly the schedule, so they try to intimidate everyone into not calling in sick.
Also remember, those of us that live in CA, you also have to option to call in "California sick." By law that cannot be used in any sick leave counseling scam. You have to call the crew desk to do this and can't do it via CCS.