No, nothing about Silksong was mentioned.
Xbox Games Showcase on Sunday, June 9th at 10AM PT, followed by a mystery Direct.

We got a hot and tasty rumor for you today. This one is courtesy of Tom Warren from The Verge, whom is known to be a mostly reliable source of insider information.

Microsoft officially confirmed today that they will host an Xbox summer showcase event on June 9 at 1PM (ET). This event will be followed up by a mystery Direct immediately afterwards. The showcase will feature games from Activision, Blizzard, Bethesda, and Xbox Game Studios, plus third-party partners. All of this is very true and not part of Warren's rumored information.

As Microsoft isn't going to just outright say what will be shown off, that is where Warren's information comes into play. He says that the post-showcase Direct will be all about the next Call of Duty installment. This Direct will be similar to last year's Starfield Direct, in which it was a however long it was look at Starfield. Only now this Direct will be a long look at the next Call of Duty title that is expected to be released later this year.

During the actual showcase itself though, Warren says we should expect to see a new Gears of War game announced. The showcase will also reportedly include release dates for upcoming Xbox titles such as Microsoft Flight Simulator 2024, Avowed, and Indiana Jones and the Great Circle.

It is also expected that we will get some sort of a reveal or announcement for Shattered Space, the first Starfield expansion. Bethesda's Todd Howard already let slip that they're aiming for a release at some point in the fall, which Warren narrows down a bit by saying he's heard it'll be out in September. In October will be the next Call of Duty, November will see Avowed and Microsoft Flight Simulator 2024 released, and December may be when Indiana Jones and the Great Circle comes out.

Beyond these specific titles, Warren did not share any information on other titles that might be shown off during the showcase. He did, however, say that Microsoft "is supposed to have a lot of games to show this year, more than the 2023 showcase."