I agree with Praetor Shinzon -- Forrest Whittaker just wasn't very good as a narrator for an eerie fantasy show. He didn't have the voice or the right kind of presence for it.
Of course, earlier TZ revivals didn't presume to replace Serling as an on-camera presence, just using voiceover narration instead -- Burgess Meredith in the movie, Charles Aidman in the '85 network revival, Robin Ward in the syndicated continuation of same. (Meredith and Aidman were, respectively, four-time and two-time veterans of the original show.) I think that would be preferable in any new version, since Serling was an irreplaceable presence.
Of course, earlier TZ revivals didn't presume to replace Serling as an on-camera presence, just using voiceover narration instead -- Burgess Meredith in the movie, Charles Aidman in the '85 network revival, Robin Ward in the syndicated continuation of same. (Meredith and Aidman were, respectively, four-time and two-time veterans of the original show.) I think that would be preferable in any new version, since Serling was an irreplaceable presence.