Conina on 07 April 2018
Well, what choice do they have? Big games take years to develop and thousands of game journalists, private bloggers, youtubers and fans of developer X are hunting down every information snippet they can get for the next project this developer (or artist or voice actor) is working on and leaks that info/rumour.
At some point these games have to be announced before someone of all the people involved in the project spills the beans. If you don't want these announcements too early you have to stay away from the internet (especially gaming sites like VGC and E3 presentations) and just wait for the TV ad of games. 
