I have vague doubts about the Necropolis and Academy winning in a long game. And even Haven might not win.
The Elves had their Light improved, the Enchanter was strengthened, and they received a strong alternate upgrade for their creatures.
For example, against Haven:
1) You can invest in Chaos and get new druids.
2) It's no longer so easy to hide from the new dragon archers.
3) The new Lukari ignore 50% of defense, making it easier to take down tough enemy units.
4) There are many other things you can do.

In a battle with Necropolis, a lot will depend on luck, especially if the Necromancer goes into Dark Magic.

Academics haven't been dominant in long games in my experience. On small maps - yes, on medium maps - maybe, but on large maps - I don't remember that happening.

For Necropolis, Academy, and Haven, it's easier to "rush" Sylvan around week 3-4.