Master strike being limited to sword in the sequel is a good choice, I had worries about other rework in the combat system but now it makes way more sense.
In the first game maces were absolutely OP, super effective against both armored and unarmored opponents. Some will say that sword did more damage to unarmored ennemies than maces which is true ( best sword deals 72 while best mace deals 61 ) but honestly against peasants and low bandits the extra damage isn't really needed since with top tier weapons you always beat them in 1-2 hits. An argument in favor of longsword was the reach but since you always end up spamming master strikes it doesn't amount to much.
From what we've seen so far I think it's safe to say that the changes introduced will add more diversity to combat as sword usage will be more about playing defensively, patience and steadiness. Also since it will be necessary to target a specific area it will require to be more observant as well taking risk to get master striked and all of that makes it more rewarding.
Meanwhile maces and other heavy weapons will be more about playing aggressively and focus more on pacing which is reinforced by the fact that combos for those weapons will be easier to pull off due to having now less zone to target ( only 3 ) which is especially a great news for people playing with controllers, and that opponents with weapons other than swords won't master strike/punish you ( which was incredibly frustrating in the 1st game ).
I was afraid that removing zone of attack in the combat rose will dumb down combat but now it makes more sense and I feel reassured.