The studio calls it balance, but the reality is that all of these changes are either nerfs to a card’s ability or an increase in the cost of the cards to better match the effect that it causes. Cards like Naga Sea Witch, Spiteful Summoner, Possessed Lackey, and Call to Arms are all going to cost more (a lot more in the case of the Witch), while Dark Pact is going to restore less health and The Caverns Below will create weaker minions.
Adjust your builds and meta outlook accordingly.
Source: Hearthstone