So, in your words, the A7 is based on the A6 which is essentially a Skoda Superb. So this would mean that, VAG group has produced a Skoda Superb, which was then developed into an A6, which has then lead on to the development of the A7, not the other way round.
So it is totally irrelevant in your eyes, that the A6 base has undergone a large development process to achieve a high end A7 and lower end Skoda Superb.
So you decide to call the A7 a Skoda Suberb, just on the fact that they have both been developed from the same base?