Final answer:
Absurdist theatre is not an example of experimental forms of avant-garde theatre by young playwrights.
Step-by-step explanation:
Theatre of the Absurd is an example of experimental forms of avant-garde theatre by young playwrights. It emerged as a response to the aftermath of World War II and playwrights in Europe, such as Eugene Ionesco and Samuel Beckett, were influenced by the horrors of war and the loss of communication. They created plays that focused on the lack of logic and the circular nature of life. Therefore, the correct answer is Absurdist theatre.