I will eat my hat if Meridian ever "approves" another manufacturer's player for integration into a Meridian system. The Meridian way is in-house, slow and as near to perfect as possible.
In general, I don't think M is really into partnerships, at least not partnerships where the partner is doing something that M could do itself. (Ferrari did composite materials on the F80 so that didn't cross into M "territory"). I have my doubts on the Faroudja thing, but only M management really knows how well or badly that has gone.
And maybe M realizes that, actually, the majority of those who are into streaming audio are quite happy with their Squeezeboxes and Sonos clients so the market is fairly limited? Just speculating...
Personally, I'm still puzzled by the G68 USB input. Great if you have a HTPC though.