he will never be truly replaced. He was the only true mickey VA. But honestly yeah, they will get a replacement eventually.
Wayne Allwine is more than just any Mickey Mouse voice actor, or at least, he is to me.
To me, Wayne IS Mickey Mouse. Not even Walt Disney himself compared to Wayne. Wayne was Mickey longer than anybody else. He voiced him for, what, 32 years. And most of those performances of Mickey in these years are what I remember of Mickey Mouse. Especially Mickey Mouse in Kingdom Hearts. This game series has the coolest version of Mickey IMO. They made a classic cartoon icon into an epic video game character. Or at least, that's how I feel about it. And yet, they never failed to keep Mickey in his typical character. And with Wayne voicing him, Mickey was awesome.
Well... that's all I can say right now on the subject, save for one last thing:
Rest In Peace Wayne Allwine