The Great Henge isnt at its best here, but as The Party Tree box topper, it still is likely to cost 4 mana or so in the mid-game and provide card advantage, mana ramp and consistent life gain
According to Mark Rosewater, new sets will be designed differently because of this change and primarily how it effects limited
The second is more short term, based on the fact that UW Flash and GB Delirium currently make up about 50% of the Standard meta, which is a historically high metagame share, and cards like Archangel Avacyn, Spell Queller, and Emrakul, the Promised End have the ability to invalidate entire archetypes all by themselves, especially in our current answer-lite Standard
One is capable of doing massive damage to the opponent's ex Pokemon, while the other can hit the enemy bench, after a small delay