I agree regarding the 'you signed a contract under Symantec' arguments. Having a quick Google, you can clearly see all of the versions that were licensed under Symantec, and then the subsequent versions released as soon as Veritas took over (Feb 2016). Therefore, if you have purchased a product using the Symantec branding, EULA etc, and you can prove you are adhering to the PUR, then you shouldn't have a problem.
Even if you have support rolling for the product, and it has been renewed under Veritas, it looks like the support contract just states SLAs rather than non-compliance issues, therefore you once again revert back to the audit clause in the EULA for the Symantec product purchased.
Someone mentioned about IP rights and whether Veritas have the rights to audit a Symantec product. A very good point. If you are in the position whereby you are being reviewed/audited by Veritas, then this is a good challenge to show that you're taking this seriously and want to know all of their ducks are in a row before coming in and potentially causing disruption.