I've been already handling it this way when I DM.
Reckless Attack and Martial Arts will become Fighting Styles.
If Barbarians and Monks are in the Warrior Group. I predict that Reckless Attack and Martial Arts will be changed to be class exclusive Fighting Styles.
Reckless attack is basically a class exclusive fighting style.
Martial Arts will likely be broken into 2 class features. Likely Martial Arts will be broken up. The Additional Attack ill likely be carved out of Martial and written similar to the Light weapons rule.
Now how it will be written is the question. Will it be written to stack with light weapons or to replace a light weapon attack.
Barbarian
Barbarian will be simple. At whichever level they get their Fighting Style, they will get Reckless Attack as their only Fighting style option.
This wll be a buff to Barbarians as they will have one of the dew fighting styles that stacks. Not a huge one ATM as fighting style feats are not currently worth the feat slot.
Monk
My prediction is that they will test it as stacking. That's right. Monks will get 3 attacks at level1. Quarterstaff, Quarterstaff, Unarmed Strike.
Fighting Style: Monk Fighting
When you take the Attack action to make an attack with a monk weapon in one hand or an Unarmed strike, you can make one extra Unarmed Strike as part of that action.
Fighter
The only question is if fighter get a class exclusive feat in the PHB or have to go backward compatible to get exclusivity.
The main thing is it would futureproof the Barbarian or Monk. WOTC could sell a book with a DEX or CHA barbarian or STR Monk as fighting style will little reference or tweaking to other class features.
Reckless Attack and Martial Arts will become Fighting Styles.
If Barbarians and Monks are in the Warrior Group. I predict that Reckless Attack and Martial Arts will be changed to be class exclusive Fighting Styles.
Reckless attack is basically a class exclusive fighting style.
Martial Arts will likely be broken into 2 class features. Likely Martial Arts will be broken up. The Additional Attack ill likely be carved out of Martial and written similar to the Light weapons rule.
Now how it will be written is the question. Will it be written to stack with light weapons or to replace a light weapon attack.
Barbarian
Barbarian will be simple. At whichever level they get their Fighting Style, they will get Reckless Attack as their only Fighting style option.
This wll be a buff to Barbarians as they will have one of the dew fighting styles that stacks. Not a huge one ATM as fighting style feats are not currently worth the feat slot.
Monk
My prediction is that they will test it as stacking. That's right. Monks will get 3 attacks at level1. Quarterstaff, Quarterstaff, Unarmed Strike.
Fighting Style: Monk Fighting
When you take the Attack action to make an attack with a monk weapon in one hand or an Unarmed strike, you can make one extra Unarmed Strike as part of that action.
Fighter
The only question is if fighter get a class exclusive feat in the PHB or have to go backward compatible to get exclusivity.
The main thing is it would futureproof the Barbarian or Monk. WOTC could sell a book with a DEX or CHA barbarian or STR Monk as fighting style will little reference or tweaking to other class features.