Here's the DB announcement...looks like the bus routes are being re-shuffled again, per the little map below:

So now the 40 is extended to the old 34/134/83 terminus at McKelvey Avenue...the 40D no longer runs on Ratoath Road, being diverted onto Cardiffsbridge Road...the 40C is now just about totally a copy of the current 40A apart from running on Tolka Valley Road (when did they stop calling this "Griffith Avenue Extension"?) and the old terminus loop around Deanstown...
Weird, wild stuff...