Yea it's true, from 2009 on, there is a totally different phone module fitted, it is from a totally different company and is oblong in shape rather than a bit rounded like the earlier Nokia unit.
Reports i have heard, suggest It has much better compatiblity and has much better acoustics than the unit it replaced. some saying the earlier unit provided inaudiable acoustics compared to as good as land line. It does however have a main plug that is only 2 rows wide compared to the Nokia units 3, so it is no direct plug in relacement, but those retro fitting it like me, have no need of the cradle connectivity and so just a 2 pin header providing power and ground is enough to give it power and it's Blue tooth Connectivity. Its MOST connectivity being the same.
New it costs only half what its predecessor did as well.