What are the list of things that were in classic but not in P99?

[Nolui Imbris]

I don't believe any have brought up some really big ones, perhaps as they are unrelated to game mechanics:

The Ocean of Tears isn't backwards, as it was classically. A few threads and the wiki page speak of this 'correction.' (I personally didn't have trouble just accepting that the headings and /locs were backwards, with the island placement being correct: aqua goblins closer to Faydwer where some came ashore in Butcherblock and the sisters being closer to the Temple of Marr in Freeport.)

The sky is different. This was changed around or with the release of Gates of Discord. Previously, there were no stars in almost all zones (I think the Plane of Sky had some) and most zones had a constant thick cloud cover; rain also brought the clipping plane to its minimum. This isn't that big of a deal in the old world, but the really unique skies in the Planes of Power zones were butchered.