It would seem that Community Coordinator CabbageMechanic was mistaken in his forum post as this has come up on Customer Support NA.

There are plans to release Micropatch 0.9.20.1_4 on November 9th, 2017

Maintenance will begin at 01:00 PDT (09:00 UTC) and will last approximately one hour.

Patch note:

• Fixed some technical issues.

During maintenance, the World of Tanks servers will be unavailable.