Coffee Seasons

When do coffees come into season? Does anyone know when coffees from the different regions come into season, I would assume that not all coffees become available at the same time. I have seen out of stocks on several coffees over the years and have never really been given an answer as to when they will be back or when they come in. Currently Klatch's Kenya AA Plus NGUVU is out of stock, but other Kenya AA's are not. Is the isolated outage due to Klatch buying from one estate? Are there any rules/ laws coverning lableing? Are some roasters selling other Kenya coffees? Please share your comments, I would like to know what the rest of the coffee world thinks.