Partial Source: The Wrestling Observer
— WWE is planning to treat the 1,000th RAW on July 23rd like a PPV caliber event.
— WWE has reached out to dozens of legends to appear at the show, including Roddy Piper, Dusty Rhodes, Sgt. Slaughter, Jim Duggan, Gene Okerlund and Jimmy Hart. They have also reached out to many names from the attitude era.
— WWE is considering having Bobby Heenan make an appearance, but his health situation might prevent him from appearing.
— Similar to the Old School RAW they did back in 2010, they are looking to incorporate several vintage production techniques to the show.
— The plan is to announce several big matches for the 1,000th RAW and then promote them like a PPV.
— WWE has reached out to The Undertaker to appear, and if he is appearing, they plan to also announce that ahead of time and promote it as much as possible.