Booked award travel with a return via CDG and one hour layover and the "you may miss your flight" message some months after the initial booking. At arrival in CDG for the ATL flight an Air France agent met five of us at the plane and escorted us via shuttle to the terminal and further escorted us through passport control and security and the maze we call CDG. Ultimately we ventured beyond any number of "do not enter" and arrived with some five minutes to spare. Without the escort the five passengers would have missed the flight and all five were in business class so rebooking would have been a challenge. So the "you may miss your flight" is not to be underestimated. As the flight was a return flight and no plans for the weekend the day in Paris would have been an adventure; but if your schedule is not as flexible a proactive approach is the better approach.