Here's a list of known perk changes lifted from a steam thread:
Fast Ad: 10% per stack (up from 8%)
CS: Not mechanically changed, but cutting injuries got reworked and buffed.
Nine Lives: Also clears existing DoT effects on proc, and grants +15 MDF/RDF/RES/INI until this brother's next turn.
Adrenaline: AP cost to 1 (up from 0)
Relentless: Now also negates the 25% Initiative penalty of "waiting"
Rally: AP cost to 5 (down from 6)
Sword Mastery: Now ups Gash Injury chances to -50% (from Gash regular -33%)
Xbow Mastery: Now includes Firearms. Handgonne reload cost goes from 9 to 6.
Head Hunter: Reworked. When you hit the head, gain a HH stack. If you have a stack the next attack will 100% hit the head, if the attack lands. Stack is removed whether you hit or miss in this case.
Fearsome: Same effect, but now also grants 20% of attacker's Resolve as a debuff to the opponent's Resolve score when dealing damage based morale checks. This applies regardless of getting a Fearsome proc or dealing 15+ damage.
Indom: AP cost to 5 (up from 3)
Nothing objectionable there, especially the end of constant Indom. via Recover/Adrenaline cycling. A lot of old strategies and builds will have to change. As a simple example new Fearsome now means the resolve check for being hit is at -36 for lindwurms, - 18 for orc warlords and ? for all the skellingtons.
Fingers crossed the Switch port is good. I would love an easily portable version of BB for long journeys.