Does SQL Server 2012/2014 Standard support Hot Add memory on a Hyper-V guest?
The phrasing might be confusing, however it means exactly what it says.

The Hot memory adding is a feature. Not a subject of limitations of the environment. 

So what the article actually says is:


You can only use the Hot add Memory feature in SQL Server Enterprise and Datacenter
Standard version of SQL Server 2012 could detect memory being added to the system, however it does not allow for hot add memory to the SQL Server so the feature is turned off


In other words, no it doesn't work.
I guess somewhere in the Microsoft office there is a dev who really really wanted people to know it wasn't his fault that the feature is limited to Enterprise and Datacenter editions. But rather a part of the licensing.