現時点でアジアポータルに情報はないので北米ポータル https://worldoftanks.com/en/news/announcements/frontline-episode-1-announcement/
原文
Frontline is available during the 1.4 Common Test only for your consideration and for preliminary testing.
Testing Frontline now does not imply the mode will launch immediately with Update 1.4.
Frontline will be activated separately from it.