To sum up everything in MKX:
-Special Forces consists of Sonya, Johnny, Kenshi, Jax (who is retired), Cassie Cage (Sonya and Johnny's daughter), Jacqueline Briggs (Jax's daughter), Kung Jin (Kung Lao's homosexual cousin), and Takeda (Kenshi's son and Scorpion's apprentice)
-Scorpion is human now, and the leader of the Shirai Ryu. He and Sub-Zero are friends and have shed their grudges.
-Liu Kang, Kung Lao, Kitana, Jade, Stryker, Kabal, Sindel, Nightwolf, and Smoke all died in MK9 and became zombies in Quan Chi's army. Some are reluctant, while others (namely Liu, Kitana, Kung, and Sindel) are happy to fight against Raiden after the events of MK9.
-Quan Chi and Shinnok die at the hands of Scorpion and Cassie Cage (respectively). The Netherrealm is now ruled by zombie Liu Kang and zombie Kitana.
-Mileena and Baraka died against D'Vorah, who was working for Kotal Kahn but SECRETLY working for Shinnok, because of course.
-Hsu Hao, Movado, Reiko, Sektor, Kintaro, Drahmin, and Moloch are all dead. Cyrax, Havik, and Kobra MIGHT be dead.
-Goro's father was killed by Kotal Kahn, and Kotal Kahn removed Goro's arms (Kotal Kahn is fucking awesome in the comics). Sheeva is currently queen of the Shokan.
-Raiden is now Dark Raiden after the events of MKX, because of course.