That is incorrect according to Adobe's documentation: Video Parameters. They are both Heartbeat variables. Neither is a custom eVar.
"Video Name" is a classification off of the Heartbeat "Content" variable, along with other classifications such as: Video Length, Asset ID, First Air Date, First Digital Date, Content Rating, and Originator. (And "Content" is actually Content ID, but named poorly.)
"Video Name (variable)" is the eVar equivalent and has the exact same value as the classified "Video Name" value, but is captured in its own dedicated Heartbeat eVar and not as a classification.
Why the Heartbeat framework has two seemingly identical variables, I do not understand. Metrics for both appear to be identical, with the exception of Occurrences which are twice as high for "Video Name" as they are for "Video Name (variable)".