Its mostly related to Osamodas.
Specifically,
Osamodas's Blessing will now give +2 Control at maximum level.
The Osamoda will be entitled to have a total level of summons in combat according to the following formula: Character Level + character Level * Control /8. For example, an Osamodas can have two summons of his level in combat with 5 Control on his equipment items and his passive at maximum level, which will give 1 + 5 + 2 = 8 Control. He may prefer to have three summons representing 2/3 of his character level in combat with the same amount of Control points.
In return, and for better management of the maximum amount of Control that a player can get, the "exotic" equipment items will lose a Control point. These items will have their other values rebalanced. Details are available in the "Items" category of this update changelog.
Therefore the maximum achievable Control via equipment items will be 6: Breastplate + Helm + Epaulettes +Belt + Weapon + Pet.
And, Rebalancing of "exotic" Control equipment items following the changes affecting the management of the Osamoda’s summons, the following equipment items will be modified as such:
Celestial Tofu Cloak: +45 HP, +3 Block, +10% Damage, +22%CMC Damage, +8 Resist.
Ratty Riot Shield: +122 HP, +22 Lock, +4 Block, +17 Resist.
Eskarina's Hammer: +1 AP, +1 Control, +194 HP, +6% CH, +45% Damage, +35% CMC Damage.
Kwoac's Leg: +1 AP, +1 Control, +196 HP, +28 Lock, +6 Block, +35% Damage, +25% CMC Damage, +15 Resist.
Seawater Neckpiece: +1 AP, +25 HP, +3 Wisdom, +16% Damage, +15% CMC Damage.
Amufafah: +30 HP, +14 Dodge, +16% Fire Damage +16% Earth Damage + 3/6/9/12% CMC Damage.
Alpha Predator Amulet: +58 HP, +14 Lock, +14% Water Damage, +14% Earth Damage, +9% CMC Damage, +5 Resist.
Dragolyre: +1 AP, +55 HP, +20% CMC Damage, -15 Resist.
Guardian Amulet: +21 HP, +14% CMC Damage, +4 Resist.
The Celestial Brooch: +1 AP, -50 HP, +2% CH, +10% Damage.
Aside from equipment losing control, don't think this affects other classes.