All modifications to the car (in most, if not all EU countries) need to be homologated (eg. approved) by the authorities. So yes, removing eCall from a modern vehicle is (legally speaking) a lot different than driving one that came without it.
Obviously, that's a nice theory but as we both know in practice there's a lot of modified cars on the roads in all kinds of way and they pass their annual inspections fine - even insurers cover them as long as you disclose the modification.
