Big News!! The 122TM is coming as the next mission marathon reward, as many people expected. Couldn't see any other posts on this, so here you all go!
According to wotexpress on VK:
• Announcement date: February 9
• ~ Dates: February 12 – 22
• ~ Possibility of purchase / additional purchase: February 12 – 25
Source:
Tank stats from supertest:
Source: https://www.reddit.com/r/WorldofTanks/comments/ld65n9/mission_marathon_coming_feb_1222/