Not true at all. Ideally, you go on track as a noob with a car you are familiar with, DD or not. A majority of the people you see at events are there in their DDs (well, seasonal DD). Certain car insurance companies WILL cover any on track crash due to the event not being timed (not competitive), and it is just a driving instruction event. I know Liberty Mutual covers stuff.
Realistically, you should not take a car on track that would set you back financially if you were to push it off a cliff.