I Have Some Ideas For New Minigames, But First, i do agree that there arent many new minigames coming out, as there are alot of MAPS for existing minigames coming out instead!
MINIGAMES IDEAS:
1: Village Defense! players fight off zombies to protect the villagers of a village!
2: The Walls: You All Know that game, no need to explain!
3: Block Party (AKA ColorShuffle): When The game Starts, there Is A Color Block in your inventory, and you have like 5 sec. to get to that color on the ground and stand there before the rest of the floor but that color falls down!
4: Skyflag: You and your team starts on an island. pretty big, and you mine trees for wood, and build to other islands, then connecting with the other teams base, and you try to steal their flag without getting killed. you can also mine the minerals on certain islands for more powerful weapons/armor!
5: Castle Attack: You and your team start in your castle/base. you can mine and destroy nearby trees to block paths, and its just like being at war with the other team!
I hope these ideas were helpful!