CindersGolightly said: "I think the mentality to take is more of the 2007 revival, not more of the film. Because the 2007 revival included (what I think to be) the best standing version of the show. Meaning, it included the better songs from the movie, but kept the classic solid songs from the original. It would be interesting to see the original with no changes, but I don't even think they license that version anymore, and it would be so boring to see that played on television, in my opinion."
I don't think they would even attempt to do the original stage version as written anyway. The film and the subsequent revivals that have preceded it have eclipsed that version. The only people who actually remember it are those that saw it in during it's original run in the '70s.
I certainly hope that they at least give some of the characters their original songs to sing or else talent like Kether Donahue, Keke Palmer and Jordan Fisher will just be heard in ensemble numbers, all their characters had solos and/or duets in the original show.
Also, since the film is so popular and iconic I don't think audiences would accept any other version than the film version, so the producers are playing it safe.
Paramount Television is the studio behind this live adaptation and they released the 1978 film.