I am not in the position to disclose how I know this or who my source is but I have it on good authority my family member in the business whose studio I mentioned before was making games for Switch, who never made games for Nintendo consoles before, they are planning something special for E3. No, I don't know what it is he just told me it's going to shock people more than their previous announcements. He also said, his friends in the industry told him there is another big AAA surprise nobody is expecting coming.
He's not, that connected he's a mid level employee but he does know which projects they are working on. All he has ever told me is which systems they are working on I never learn which games he worked on until after they come out. But the one they did on Switch so far was an out of left field surprise many have cited as part of the proof 3rd party support is improving.
That being said, I trust him. I don't have any real insight but based on his past excitement for working on Switch knowing his studio was anti Nintendo because of the Wii/Wii U and previous policies from the past, if he says something truly big and surprising is coming I have reason to believe it.
He also says expect a bombshell from Sony, a real bombshell. I don't know what to expect I asked is it PS5 he didn't give me an answer just it will be big. He told me when PS4 would be announced because they did a close to launch game for it.
Inside rumblings all he said is there are people in the industry that are expecting the Switch changed the industry and there is no going back.