Merge branch 'aa-column-drop-remove-after-release-date' into 'master'

Column drop `remove_after` to be the release date of the M+2 milestone

See merge request gitlab-org/gitlab!41852

doc/development/what_requires_downtime.md

@@ -30,14 +30,14 @@ places. This can be done by defining the columns to ignore. For example, to igno
 ```ruby
 class User < ApplicationRecord
   include IgnorableColumns
-  ignore_column :updated_at, remove_with: '12.7', remove_after: '2019-12-22'
+  ignore_column :updated_at, remove_with: '12.7', remove_after: '2020-01-22'
 end
 ```
 
 Multiple columns can be ignored, too:
 
 ```ruby
-ignore_columns %i[updated_at created_at], remove_with: '12.7', remove_after: '2019-12-22'
+ignore_columns %i[updated_at created_at], remove_with: '12.7', remove_after: '2020-01-22'
 ```
 
 We require indication of when it is safe to remove the column ignore with:
@@ -45,7 +45,7 @@ We require indication of when it is safe to remove the column ignore with:
 - `remove_with`: set to a GitLab release typically two releases (M+2) after adding the
   column ignore.
 - `remove_after`: set to a date after which we consider it safe to remove the column
-  ignore, typically within the development cycle of release M+2.
+  ignore, typically last date of the development cycle of release M+2 - namely the release date.
 
 This information allows us to reason better about column ignores and makes sure we
 don't remove column ignores too early for both regular releases and deployments to GitLab.com. For