Is this an official statement from Mozilla? If understood right, it says that because every tracking site already does, we will put it inside the browser. It seems like one day Nike will say, we need to send the location of every step you take, where you're heading and the speed so we can make better shoes. And people just, yes, seems fair to me.
It's more like Nike are fitting their stores with a special floor that track people walking around in the store to figure out where people go and what they find interesting.
There are many vendors of these special floors, and they offer different kinds of reporting to Nike.
At the moment, Nike can't use multiple vendors without careful testing because the floors can potentially interfere with eachother. Sometimes the interactions only occur in extreme cases, such as massively overweight or underweight individuals. Nike may not be floor experts and not know how to to this. It also makes the floor "thicker" with multiple vendors special floors layered on top of each other, which might feel weird walking on.
These vendors don't just sell to Nike, they sell to lots of stores. Obviously they don't share Nike's "data" with ASIC but each of them have to deal with the fact that even if they solve the problem for Nike's chosen set of vendors, they'll have to do it again for ASIC as well.
So, the floor vendors got together and proposed a mechanism whereby they can all work together.
No new privacy leak, no new information is being generated, or even being transmitted to anyone who didn't already have the ability to collect it, but the implementation is simpler, and user experience is better.