If you're going to remove something, replace it.

I understand removing team builder, games took WAY LONGER than it should. And about 35% of it was waiting in the lobby waiting for a jungler or a support to show up. But since Riot is removing Dominion, a map I use as a tool to... well. I think you should replace it with something else. We're accustomed to the 4 map League of Legends. And lowering it to 3 will create a gap that will never be filled.