Maybe the 2009-2010 model is based on 2720-2820 family?
Or 7200-7500 family ?
I just took some time to review all discontinued items by Garmin and ordered them by year. The first with XM was 2720.

Looking at Honda parts nr.:
Navi 2006: 39201-mca-a81
Navi 2007: 39201-mca-a81
Navi 2008: 39201-mca-r00
Navi 2009: 39201-mca-r40
Navi 2010: 39201-mca-w30
Navi 2012: 39201-mca-s81
So two release of 2006-2008 and two release of 2009-2010 models ???