The VCAP-NV Design 2021 certification validates you can gather customer information, including requirements, risks, constraints, and assumptions, and use that information to make design recommendations for NSX-T Data Center solutions.
If you have 1 of the last 3 VCP certifications released, you can take the current VCAP exam and get certified as long as your VCP is within the last 3 VCPs that were released. Example: VCP-2019, VCP-2018, VCP6 qualify but a VCP5 does not.
No. Please see this blog post for an explanation of this policy.