I imagine that M sees the markets for multichannel DSP systems and 2 channel passive speaker systems as quite separate, hence no 562 equivalent in the G range.
The lack of tuners is IMHO due to 2 facts:
1. FM will (in the UK at least) be switched off in the forseeable future, so folk are unwilling to spend a lot on an analogue tuner which won't have anything to tune into in a few years time.
2. Quality of DAB transmissions in the UK is not great, so folk are unwilling to spend a lot on a digital tuner.
Mark S