I was looking through the new race options for PCs in Volo's Guide to Monsters and noticed they included the Goliath. About 2 years ago the Goliath was also published in the Elemental Evil Player's Companion supplement.
Comparing the two, there haven't been any updates or changes added in Volo's Guide.
So I'm left wondering: why did the designers decide to include a race that's already been published instead of creating a new one or just leaving it out?
My initial thought was that the Goliath might just be really popular and because the Elemental Evil Player's Companion is technically a supplement for the Elemental Evil story line, not many people would have bought it for use with any other campaign. But if that's the case, why just the Goliath? Why not the other races? Was it just because the Goliath won the popularity contest?
(I know the Aasimar is also include in Volo's Guide and the DMG but I have yet to compared the two to see if Volo's Guide is a more solidified option than what was suggested in the DMG).
Answers should cite actual quotes from the designers rather than speculating.