https://thearmoredpatrol.com/2025/05/13/wot-tiered-lootboxes-in-eu-na-asia-servers-with-tier-10-chieftain-mbt-b/

First rollout of new lootbox sales in global servers, these are the multi-tier lootboxes chinese server played around with for their chinese new years event.
MBT-B and Chieftain MK.6 are your new whale tanks, arguably more than the WT E100 that went for 100k gold.
Thankfully ever since I got the Lion I don't feel compelled to whale for MBT-B anymore, but this is a historical leap in monetization.