Enterprise Architect allows to define an Initial Value on the EnumerationLiterals, feature that does not exist for UML EnumerationLiterals.
The option ea2md.semantic.enumeration.convertLiteralsDefaultValueToProperties in the publisher.properties controls the conversion of the EnumerationLiterals with an InitialValue into Properties with a DefaultValue.
The conversion will be done on all the EnumerationLiterals of an Enumeration if at least one of the EnumerationLiteral has an InitialValue.
Set to following option in publisher.properties file:
# Enable publishing Enumeration's EnumerationLiteral as Properties to preserve the default values. The conversion will be done if at least one EnumerationLiteral of the Enumeration has a Default value.
# Available values: True, False - default: False
ea2md.semantic.enumeration.convertLiteralsDefaultValueToProperties=False