What AvTvM is talking about is spot metering, where the metering is done exclusively (not 'weighted' to some unknown fraction) at a small spot (1.5-4% of the field, depending on model). Those long statements from Canon about iFCL metering which you posted are referring to evaluative metering, and yes, that's been weighted toward the selected AF point for a long time. It is very unfortunate Magic Lantern is not able to fix most things outside live view - but well, never look a gift horse in the mouth. Examples of this are afma (dropped on the 60d for the 7d) and Ec on m (no dice on 5d) - so unless you can come up with a commercial reason for Canon to implement it, forget it.

And between mid-range and top cameras this will concern features that are important if you are an advanced photog. Furthermore, they have to differentiate their products.

To achieve the sales goal, first they have to competitive, so they of course provide the basic feature set (like 3x bracketing) and cover up for problems (like in-camera hdr & multi-shot nr). And 2) maximize money flowing to them (sell as as much cameras as they can and as expensive models as they can). This means: 1) minimize costs (like recycling the 5d2 sensor for the 5d3 and have as little support/testing for seldom used firmware features as possible). The question just is: What does Canon want? The answer: Maximize profit. A company designing the 1dx surely is capable of implementing much more features in firmware than are currently available.

Canon 7d firmware new features