Publisher (and developer) Devolver Digital is hosting an E3 event, they confirmed this via Twitter. 
Devolver does both games and movies, and they’re mainly known for stuff like Broforce, Genital Jousting, Strafe, and Hotline Miami. 
Devolver is mainly a PC and PlayStation developer/publisher, so expect to see a lot of announcements for these two platforms. They have 7 upcoming games that we know of including Ape Out and a new Serious Sam title. 

Devolver Digital will have an E3 press conference this year. Please stay tuned for a time and date. pic.twitter.com/WoHiOaio4G

— Devolver Digital (@devolverdigital) May 16, 2017