Possibly a limitation for the minimum size of a hardback due to the spine. There's 1E modules as small as 8 and 16 pages. As noted above most printers require a signature of at least 4 (2 sheets of 8½X11, front and back) or 8 pages (known as a "signature") is the smallest block of pages you can do. So we'd see books in pages of 32, 40, 48, 56, 64, 72 or such.
He didn't say that it was divisible by 32. He pointed that 32 seems to be the minimum number of pages WoTC will have in any of it's books.
I hope that the Planescape book will be as thick as Keys From the Golden Vault. You can't describe the planes and their planar inhabitants in just 32 pages. 
Very few people know the original derivation of 'berk' - it's seen as very mild (and now rather old-fashioned). IIRC, it was even allowed in Parliament, until some spoilsport alerted the officials to the original meaning.
He was quoting this post by @TheGlenHe didn't say that it was divisible by 32. He pointed that 32 seems to be the minimum number of pages WoTC will have in any of it's books.
Berk comes from the rhyming slang of "Berkeley Hunt" which rhymes with a word that can refer to a part of the female anatomy.
Does anyone remember what Berk referred to in the Planescape setting?
From Sigil and Beyond: "A fool, especially one who got himself into the mess when he should have known better."
If we're lucky, maybe WoTC will update 3e's Manual of the Planes to 5e. I liked how that book mentioned what kind of gravity each plane had (objective vs subjective) and how each plane affected the nature of certain spells (heightening spells with one kind of descriptor while diminishing spells with another kind of descriptor). The latter in 5e will probably involve casting spells with Advantage or Disadvantage.
