Two new splatoon weapons, as well as, a new map will be arriving on Splatoon 2 next month, July 2018.
The first weapon, Kugel Shriver, is a new type of weapon that is equipped with a transmission system. The weapon starts with a shaky short range but slowly stabilizes to have a greater distance and accuracy. You can recharge your weapon while shooting by pressing the ZR
The second weapon, Explosher, is a new kind of heavy slosher. When shot, the ink blots will explode when it hits the ground or wall. However, due to its weight, it is a slow weapon.
Lastly, the July update will bring along a new map called Hotel New Otolo. The map is set in a rooftop pool in the middle of the city.
You can view videos of the two weapons below: