• Removed: In domain Spam Filtering, domain admins can no longer modify (or see) individual weights for any spam checks. If a domain admin has previously modified the spam check weights for their domain, performing an upgrade to this version will revert that domain to using the system-level spam check weights. You may wish to inform domain admins of this change and advise them them to monitor their email and adjust their domain's spam filter actions accordingly.

• Previous value for medium spam: 20
• New value for medium spam: 16
• On the System Anti Spam page the new value is shown: 16
• However, on the domain's Anti spam page, the old value is preserved: 20
• When I look into the domain's settings.json file, I found that the values are saved per domain (see below) and are not updated on System wide changes. This is different than the explanation given by Kyle. Also, it is indeed not possible to edit the value through the UI.
• Incoming mail to the domain are still filtered using the value on domain level (20) instead of the system level (16). I have checked this in the headers of multiple messages (see below)

Global system anti spam settings:

"spam_settings": {
    "allow_users_to_override_spam_settings": true,
    "enable_spam_override": true,
    "spam_forward_option": 2,
    "spam_forward_override_active": false,
    "spam_level_low_weight": 15,
    "spam_level_low_action": {
      "action_type": 6,
      "argument": "[?SPAM?]"
    },
    "spam_level_med_weight": 20,
    "spam_level_med_action": {
      "argument": "Junk E-Mail"
    },
    "spam_level_high_weight": 30,
    "spam_level_high_action": {
      "argument": "Junk E-Mail"
    },
    "spam_relay_option": 1,
    "spam_relay_override_active": false
  },