Why does Blue Buff no longer give 2 AP per level?

At the beginning of season 7, Red and Blue buff were changed to last for 90 seconds (beyond the first) and have additional effects. Red buff dealt it's DoT as onhit damage in addition to as a DoT and Blue Buff gave 15% AP instead of +2 AP per Level.

This was later changed so buffs lasted 120 seconds always, Red buff no longer applied it's DoT damage onhit (in addition to being a DoT), and Blue Buff lost it's +15% AP.

However, Blue buff was never given it's +2 AP per level back for some unknown reason.