Apart from sitting the latest VCP exam what other VMware exams will renew my VCP status?
I guess the NSX exam will but would the vSAN 6.x specialist also renew my VCP status?
Here's the policy, which should give you the general idea: Recertification Policy
The specific exams/certifications for you would depend on which VCP you already hold.
vSAN Specialist is a "badge" - as you'll see from the policy you need a VCP or VCAP to recertify a VCP.