I wouldn't say that the server is "full of" unclassic mechanics by design, but there are a few here and there.
Roegan saying no to classic DA aggro dump despite overwhelming evidence.
Making necromancer lifetap spells unclassically resistable to fix an issue with Ivandyr's Hoop, an item that no longer has any raid relevance.
Classic pets that can dual wield 2H and weighted axes
are deemed too OP for P99.
The hard-coded 25 mob ae limit was made more in the interest of balance and preventing server disruption than classicness.