You don't need to change it at all with a new edition. Revealing what was always there because of a new addition is not a change to the setting. A change would be if a race was known to be there and it vanished because of a new edition.
For example, when Dragonborn came out and were revealed for the Forgotten Realms, they didn't need to crash another planet into Toril for them to be there. They could just have just have new products have them present as if they were always there and there would have been no issue. However, because dragons and dragon blood is so powerful, Dragonborn in my game are around CR 5 right out of the gate without any class abilities placed on top, so they are not usable as a PC race. That is a change to the setting for my game as a known race is not the same as it was.