FromSoftware are most well known for their Souls and Bloodborne games, both of which feature a mysterious, minimalistic lore as well as protagonists that are silent. Sekiro: Shadows Die Twice will have some major storytelling changes.
Demon's Souls, Dark Souls and Bloodborne all shared similar combat, but the one exactly same thing they all had was a mute protagonist. Each of the games featured character creation, which resulted in having a blank state hero, so it's possible that FromSoftware cut on major costs by deciding not to voice or give dialogue to the characters, due to virtually infinite variations in creative possibilities.
Sekiro: Shadows Die Twice will instead have a pre-established protagonist, who will interact more with the people he meets. In a recent with Game Informer, Yasuhiro Kitao the marketing and communications manager at FromSoftware, confirmed that The Wolf will indeed talk with the people he meets.
Technically, there were bits of dialogue with characters in previous games as well, such as the Emerald Herald, but the protagonist was always mute. As for The Wolf, Kitao stated that "He'll say a few things here and there, but yeah, he won't bore you to tears with constant monologues".
This statement goes hand in hand with Kitao's previous answer to one of the questions, where he said that despite feudal Japan's bright colours, Sekiro: Shadows Die Twice will not be a cheerful story and will follow FromSoftware's now iconic storytelling tone.
On top of that, having a voiced protagonist offers another way of telling a story - flashbacks. Kitao confirmed that this method will also be used, but the developers will not use it too much, as this will be a game mainly focused on its present.
This development goes to show that games can indeed become better and more advanced with newer titles, as Sekiro: Shadows Die Twice not only offers a voiced protagonist - it also has a combat system that looks familiar to any Souls and Bloodborne fans but will still be vastly different due to pacing and the new possibilities from The Wolf's prosthetic arm.