My kids went through K under the MCPS internally created "everything is a P" grading system. My favorite was the metacognition category. I remember asking the teacher what it meant to be proficient in metacognition. She answered "I honestly just don't know. None of us do so the kids all get a P for metacognition." I laughed and then started running the numbers for how much private school would cost for 3 kids.
We also received ours a while ago. 4th and 1st, not K but I don't see why it would be different for K. Can you ask around to see if others from your school received them?