From an EK business standpoint, this only makes sense. When you are looking to maximize revenue, this is a fantastic way to do it. Cat C wider eligibility tickets are currently around an ID 50 rate and available to a fairly large range of family members. It would only make sense to extend this to friends as well. These are firm seats, not ID 90's, so your friends and wider family members will not have to worry about getting bumped (under most circumstances) This is a huge plus for you as you don't have to stress worrying whether they will get on. From a company standpoint, the reason this makes sense is that it will help EK fill up those last few seats with a reasonable fare (from the US, a cat C wider eligibility ticket still costs around 750 USD for economy and around 2300 USD for business). When they chose to release those seats remains to be seen. This is just my opinion, but if the company was smart, they would extend the wider eligibility tickets to include friends!
The downside of this is to those who use ID 90's on a regular basis. Wider eligibility tickets are firm, and thus cut down on the number of seats avail to standby travelers should people actually use them. They are not cheap, so that remains to be seen.
All in all, and this is just my opinion, this is a step in the right direction that makes sense for all. Lets just wait and see what comes of this and what they do to screw it up. Fingers crossed it will be good for all.