Holiday ops, Starts on Wednesday the 8th, Loot Boxes are available on the 8th -10th and run until January 10th. Advent starts on the 1st with a daily mission and the first Tank from the Advent Calendar to drop would be Thursday the 2nd when the Advent Calendar Tanks begin to Drop.
Caliban – Tier 8 British
AMBT – Tier 8 USA
Bofors Tornvagn – Tier 8 Swedish Heavy Tank
M-IV-Y – Tier 8 USA this is the tank with the new mechanic a la the Is3a and the 703-2
M4A2 T-34 – Tier 5 Russian, Just like the Fl10 from last year,
Pz.Kpfw. 35 R – Tier 2 German
A43 BP prototype – Tier 6 British Heavy tank
We just need a two or three low Tier Tanks to fill out the list.
The Loot Box contents are just speculation at this point, can't say anymore.
Source: https://www.reddit.com/r/WorldofTanks/comments/r186oi/advent_start_and_loot_box_tanks_2022/