Lea, or Axel, is a recurring character in the Kingdom Hearts series. He was one of the primary antagonists in Chain of Memories and Kingdom Hearts 2. The character is expected by fans to be making a return in the upcoming Kingdom Hearts 3.
It's been awhile since we heard anything about the game's development from Square Enix, with much of their current focus revolving around Final Fantasy XV and the VII Remake.
A Kingdom Hearts fan recently asked Axel/Lea voice actor Quinton Flynn about whether he'll be reprising his role in the upcoming game, to which Flynn responded that he simply hopes so.
He stated that he has not yet received news about whether he'll be reprising the role, and is waiting and hoping to hear from Square Enix soon.
Fans can't really see Square Enix changing voice actors for the character, since he played the role twice already, so it stands to reason that voice acting for many characters in the game simply has not started, and will be added at some later point in the game's development.
We'll bring you more news about the game as it happens.