I’ve tested this in 4.7 and 4.8, and I can’t see that the behaviour has changed between these two versions.
For User Defined Enums (the enum assets you create, rather than C++ enums) the Data Table editor UI has always shown you the “NewEnumerator0” style names, and the CSV importing has only ever worked with the “NewEnumerator0” style names. I asked the Blueprints team about this, who confirmed that the internal enum name is immutable, and what you’re changing in the enum editor is the display name - this is done to avoid losing references when renaming enum entries.
I can change the Data Table editor to show you the display name in the data grid, but the CSV exporting and importing is likely best using the internal enum name to avoid referencing issues when renaming your enums. I could have the import fallback to using testing display name if it doesn’t find a match, but this would be vulnerable to data loss if the enum entries were renamed and some old CSV data was re-imported.
It is worth noting that this issue only affects User Defined Enums, and that C++ enums will always use the name of the enum entry defined in code for their CSV import/export.