They probably did this on purpose.
Had they communicated a second pvp fresh server ahead of time, many horde would have held off a couple weeks/days in anticipation.
By locking Skyfury down with no warning or communication, theyve engineered a reality where both PVP servers might have good faction balance for a while.
The bother is that they did it too late. Skyfurys population is entirely too big. The other bother is people who are cut off from their friends Berlin Wall style.
Someones gotta start over or someones gotta play alone. Blizzard are genius innovators at creating lose-lose player experiences and then having Ion say “we hear you” in the next streamer-dev interview.