There is no direct replacement exam, the retiring 6.2 exam is the last on NSX-V.
After the retirement date, the NSX-T derivative will be the only way of achieving VCP-NV 2020:
Is there any exam (VMware Certified Professional 6 - Network Virtualization 6.2 Exam) extension due Coronavirus pandemic?
No extensions have been mentioned anywhere.
In-person testing has already resumed in many countries, and remote proctored testing has been available for weeks now.