On this link, what is vRouter? I think this is not NSX-T component and telco vendor original virtual machine appliance based router. Is it correct? If yes, I would like to now some products name as sample.
You are correct that is from a specific vendor and is a generic name to put on it is deployed on the ESXi host I don't know why it pointed as a hypervisor that is kind of confusing since gives the impression of being embedded or something but is not the case.
If you are familiar with a vendor just put a name on it for example contrail vRouter, or X vRouter is not tied as well to VNF's vendor just is something that the vendor place as an SVM for just make routing in this specific case for enabling EVPN on NSX-T as a pre-req. so technically talking it could be VM part of a VNF doing routing that can work but also can be something from traditional NEP that has the capability to speak EVPN as is pointed in the doc as well.
hope this helps!