There weren't that many "positive white characters" in there and one cannot broad brush to say that no "positive" whites existed. If they didn't, "we" (editorial, and me, specifically - "blacks"
probably wouldn't be here today, let alone with a Barack H. Obama as President.
IMHO, if they are going to re-do it, they should also do the full thing to include "Roots II: The Next Generations" (which I believe followed Haley's maternal side), as that miniseries covered from the Civil War through to the 1970s and included Reconstruction, Jim Crow, WWI, WWII, and the Civil Rights era.
As FYI, I was in high school when the original aired and I have watched it many times since (and still have it on tape), and although the actors and actresses (back then dubbed part of an "All Star Cast" 
) are all now "dated", the material is still pretty vicious and heart-breaking.
If anything, what hadn't been shown before then in any documentary or docu-drama of this subject, was the society and rituals that had evolved in the small villages of African countries like Guinea (including the presence of Islam there). Previously, the only thing that most could conceive about any African country (where most, even today, keep referring to the continent of Africa as if it were a country) was the bullshit shown in the endless movie serial and television series "Tarzan" or the animated "Kimba". But most notably, Roots showed the harrowing "Middle Passage", something that had previously been relegated to display of the same old illustrations of "close pack" and "loose pack" (with respect to how the slaves were loaded and managed in the ship holds) where men and women were chained prone to wooden planks, row after row, and level upon level.
Haley was actively involved in the original and the danger now (although knowing alot of the story was originally "Hollywoodized" is trivializing and glossing over the history to soften it - especially in this era of rightwing lunatic ownership of almost all of the media. And as an example, although the original clearly showed African involvement in the trade with respect to Kunta's (and others' capture), there will be those demanding to remove any white involvement whatsover in the transactions and transport. So I expect as this project evolves, it will get quite ugly (although there are many more scholars in African and African-American history out there now to debate it, all of whom have accumulated and published quite a bit of primary research over the past 35 years).
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