Blizzard will be releasing the aforementioned fresh realms feature to facilitate new players who want to begin playing WoW Classic upon the release of Wrath of the Lich King Classic.
This is one of the several changes to Classic that Blizzard is implementing ahead of the launch of Wrath of the Lich King Classic.
Wrath of the Lich King Classic has no release date as of yet but it is expected to launch later this year.
In the same vein, Blizzard is now working on releasing Wrath of the Lich King Classic to give classic players more content.