Tracked it down.
Holy hell it's a lot of...words. It may be a great setting for Shadowdark campaigns, but it's not the same presentation.
Back in the 80's I would stay up late reading stuff like this, but now I really appreciate terse, zero-prep format. Maybe a campaign setting can't be zero-prep in the way a short adventure can, but I'd really love to see something other than long form prose.
If you're talking about the 3e Necromancer Games Wilderlands of High Fantasy, yes there is a lot, but you certainly don't need to read all of it. Choose or randomly determine a start hex, you only need to read up on the few surrounding hexes. The 3e Players Guide gives a nice setting overview, but the whole point of Wilderlands is it is bottom-up and built to facilitate GMing. Eg when one PC decided to fly hundreds of miles to sell an artifact to the Green Empress, the book gave me a ton of hex location material for the journey.