At your DM’s option, you can select eladrin as the subrace for an elf character, instead of one of the elf subraces in the Player’s Handbook. (same UA article)
Members of a subrace have the traits of the parent race in addition to the traits specified for their subrace. (PHB 17)
Eladrinegenskaperna läggs till basdelsegenskapens egenskaper (elf).