Sure, so? Is that mandatory? No. Would it require explicit user permission? Yes, as any other device or service in EU. The user or the manufacturer always have the ability to put extra devices which do whatever, if they respect the current regulations. This has nothing to do with having eCall installed by default.
Note that the linked document applies only to eCall In Vehicle System. Nothing prevent manufacturer to install a second system, using the same or separate modem, and track user's location and actions continuously. If the law requires you to install a GPS receiver and a modem, it would be uncapitalistic not to try to gain some profits from the data.