(That’s my video)
This is strange - these used to be in the “Miscellaneous” section of the Content Browser, but for some reason it’s now not there in 4.25. I’m not sure if that’s intentional or not, but they don’t belong to any special modules or plugins so it must be an oversight.
Essentially it’s just a wrapper class for a Static Mesh asset that converts the mesh into Slate vertices. I can’t find any references to the factory class nor the type in engine source, so it must have been removed by accident or the menu isn’t showing it for some reason.
EDIT: Definitely a bug. There is no AssetTypeActions class for USlateVectorArtData, and the factory seems to require that to show it in the menu. Bit dumb.