Well, sorry, but this is some bad news. As much as many of us are looking forward to getting more information about the sequel of Hollow Knight, Silksong, especially while E3 2021 is just around the corner, and we naturally expect to get all sorts of news, announcements and further details from the games that we are interested in on this occasion- but, it's very likely we won't hear anything about this one after all.
On developer Team Cherry's Discord channel (and via Hollow Knight subreddit), it was revealed that they've got no announcements or blogs scheduled for this year's event. Well, at least now you know not to get your hopes up.