Shuttles are notoriously unreliable in Paris. If their driver doesn't show up that day 'ah well' and they won't let you know. If they miss you somehow, they will deny their responsibility and keep your money.
At this hour, get a taxi from the official taxi queue (never in any airport or train station go with anyone who pretends to be a dispatcher (they like to wave clip boards) who approaches you; they are scammers and the trip will rip you off. Find the official taxi queue and get in line; it won't take long at that hour.