You're missing the point.
M cars (The proper M Cars, not that X6M junk) have always been known for their relatively high revving Naturally aspirated engines. It's something of a selling point of the cars and it has been for the past 32 years. Changing that tried and test recipe all of a sudden is going to cause a stir amongst enthusiasts espically when the only creditable reason for the change is the environment/CO2 figures.
Oh no i totally get the point, but i dont agree with it
My opinion is that people babble on about cylinders and natural aspiration but to me the importance lies with the car being a driving machine.
If you look at some of the older M-cars such as the e30, e36 and e46 3 series, you have a 4 cylinder and 2 6 cylinders in that lot, but the cars them selves are very well regarded, Hey the E30 even reaches true classic status, all that from a 4 cylinder.
Basically i think that those M 'enthusiasts' as they call themselves are too focused on M cars being naturally aspirated and a lot of the time say things like " omg only X clyinders wtf ?? "when all an M car needs to be in 'The Ultimate Driving Machine', personally thats what i think is important.
So if its got a 4.4 V8 thats hardly a bad thing, because realistically 4.4 is big, and when you whack two turbos on it i imagine its pretty fun as well does any of this matter in the realms of the car being the ultimate driving machine? No (personally) its still going to sound MEAN as hell either way