But our group, lv 9 when the feature was unlocked, had all except the last one unlocked.
And now, it is lv 6, still the same, I believe some group that upgraded it to lv 8 is also the same.

Is it because it was an addition to the game so every group automatically have it unlocked to their current group level and need to upgrade this skill to have it unlocked further? Can someone whose group recently leveled up verify this please (for example, 5 to 6, see if lv 6 activity is automatically unlocked or require the skill upgrade)