M+ Season 2 to Season 3 Keystone Level Drop Confirmation?
Has there been any confirmation how many levels a keystone will drop going form this week to next? I want to know what level keystone I should complete in order to ensure I have at least a 15 for next season start.
BFA Keystone Season 1 → Season 2 = Mythic Keystones will go down by an additional 3 levels when the season transition occurs
BFA Keystone Season 2 → Season 3 = * Mythic Keystones will go down by an additional 3 levels when the season transition occurs, to account for this difficulty increase. So if you do an 11 this week, instead of getting a Level 10 keystone when Season 3 starts, expect a 7.
Shadowlands Season 1 → Season 2 = They dropped by 3 levels.
… Since there’s been no confirmation, we can only use history, so, why are people saying we need to do a 20 this week on time in order to get a 15??
Hello Krystallíne!
When Season 3 begins next week, Mythic+ Keystones will be lowered by an additional 3 levels to account for the overall increase in dungeon difficulty. If you’d like to open your Great Vault next week and earn a +15 Keystone, you’ll need to time a +18 or complete a +19 untimed before next weekly regional maintenance.
Hope this helps clear things up. 
I’m still here Birds!
Mythic+ end-of-run drops will cap at Mythic+10 throughout the week of March 1–7, and Season 3 Rated PvP gear upgrades are initially capped at Rival II (base item level 268) until Mythic Difficulty Sepulcher of the First Ones is available.
Completing the Great Vault participation requirements next week, March 1–7, will reward the new item level thresholds in the March 8 Great Vault after the weekly maintenance.
Season 3 Great Vault Rewards
| Difficulty | End-of-Run | Missed Timer | Great Vault |
|---|---|---|---|
| Mythic+15 | ilvl 262 | ilvl 259 | ilvl 278 |
Class set pieces, excluding shoulder and chest, will appear in the Great Vault rewards starting on March 8 from all vault categories. Defeating raid bosses that drop tier will increase your chances of receiving that tier slot from the Raids row. The shoulder and chest pieces will appear in the Great Vault rewards from March 15 and beyond.
Fuente