The Exhaustion is only on the Berzerker subclass, but it seems they will not be implementing this into the game.
A "feature" that Larian are wise not to include in the BG3, as it should have been dropped in errata years ago, or with Tasha's changes. It's the number 1 reason no one plays berserker in 5E.
The free Long Rest spam would largely negate even severe Exhaustion in BG3 anyway.
Berserkers are ridiculously OP compared to other martials right now. Especially since they get that extra attack or Enraged Throw with Bonus Action. Larian have also added items that grant MORE bonus actions and are spamming Potions of Haste everywhere. BG3 Berserker can get
4 attacks per turn easily before level 5, when they will have 5 attacks. That's completely absurd.
They should redesign the Exhaustion from Frenzy so that it would be significant but not crippling. Frenzy is too powerful and it needs some balance. Or tone the class down in some other way.
And the extra Bonus Actions from items need to go completely.
