I might not have detailed it well enough. It's part of the bigger issue of Fairness.that does not sound like anything I have ever even heard of
A New School game is Fair. The most common example is that a character will almost always get a save or check to avoid any effect. Another is where the DM will give helpful descriptions with highlights to hint at things...and specifically traps as the player and character nearly always must be given a chance to see or figure out something before it happens. And it is rare to the extreme for NS to have any trick or "gothca" where a player falls for something that effects their character.
Old School is Unfair. A character might get a save or check, if the DM feels like it. A lot of things that effect a character are unavoidable. The DM will often describe a area in detail, but treats everything equally. Old School is full of tricks and "gothca" bit for players to fall for.
Yes anything can be in any individual game.These are not differentiators between old school and new school. These can exist in any game.
Broadly speaking though the "most" will apply. And that is more then 50%. Maybe 75%. But it does not mean every single game of that type ever.