Was a bit more than 81 https://www.reddit.com/r/classicwow/..._cleared_naxx/
World buffs are not important for Naxx, if you're progressing as a normal guild you'll die and lose them. When Naxx was released on the last good private servers, it was tuned higher and world buffs were turned off for the first week or 2. Consumes will be needed.
Would actually be really cool if one of the guilds who are going to breeze through it, did their first run with zero world buffs and consumes. We all know that won't happen though.