It depends on whether you buy the phone through Virgin Mobile or its partnership with Apple. If that is the case, it will be unlocked (DSU and ISU) on request after 14 days.
If it is a BYOD, then Virgin Mobile cannot unlock it.
VM, you really need to stop being evasive. Will it work., REGARDLESS of where you buy the phone. You need to start supporting your customers and not just your business partners.