These two fields allow to specify a different default assignee for ticket opened against this package in bugzilla. Note: The EPEL field is always displayed for packages in the 'rpms' namespace regardless of whether it is used in bugzilla or not.
gmpy has been superseeded by gmpy2 long ago; the latter is actively maintained upstream and in Fedora. https://fedoraproject.org/wiki/Changes/Mass_Python_2_Package_Removal is a good time to retire gmpy before Fedora 30. This fixes bug #1627181.