Here's how I understand it.
The certification will not expire, but if you want to avoid training etc. in the future, you will have to pass an exam for a newer version as long as it is available for your current state.
According to VMware Certified Professional - Data Center Virtualization 2019 (VCP-DCV 2019) you just need to pass the exam for the current version if you hold VCP5-DCV or newer. If you however hold VCP3 or VCP4-DCV, you'll have to start from scratch, i.e. attend a training, and pass the foundation, as well as the VCP exam.
You're a VCP6.5-DCV for life, and July 21st has no significance now.
If you decide to upgrade to the latest version at any point in time, you'll need to meet the requirements as defined at the time.
VMware are allowing an exam-only upgrade path for holders of the previous 2 major software versions.
The current VCP-DCV is 2019 - if you want it, check the VCP5 or VCP6-DCV path here: VMware Certified Professional - Data Center Virtualization 2019 (VCP-DCV 2019)