Well the party in the gameplays were level 3 tops, so I do not think they have it ready (feats are at lvl 4 minimum)
I think they didn´t show the UI for character level-up. A pity I wanted to take a peek to see what subclasses you can pick.
I've noticed in the gameplay videos, that Shadowheart casts Guiding Bolt often. She usually has a weapon and shield equipped when doing so. Guiding Bolt requires a Verbal and Somatic components, how can she cast it without the Warcaster feat? I'm not complaining, just trying to figure out Larians spellcasting system. It makes a huge difference for my planned spellcaster builds.
Shadowheart is a cleric, and clerics(and paladins) could bear the holy symbol in his shield. And as RAW, you can use the hand where you have your holy symbol or druidic/arcane focus or bard instrument/weapon focus to make the somatic components of a spell. So she can cast spells with somatic components with weapon and shield.
Sc:
https://www.sageadvice.eu/2015/01/04/holy-symbol-on-shield/That said, I do not think they are going to implement fully all the spellcasting rules: the components in the component pouch, holy symbols, etc
Warcaster is still useful for bards or to use spells as your AoO reaction.