An idea for the story....
The opening scene.....is an EXACT re-rendering of the original. Bring back Drew...bring back the guy who played her boyfriend all tied up.....recreate that house and kitchen......and have everything play out the same, except that Drew lives, and injures the masked killer, who gets away. The murder of the boyfriend is pinned on Drew, who is so injured and traumatized by the whole situation that played out....that she's comatose and sent to an asylum. (A little cliche, sure....but the Scream movies were MADE to goof on horror film cliches). Cut to present day. Now...you can have cameos by ANY of the old cast....because technically...a different future played out and none of them necessarily were killed. All we know is...Drew is locked away and catatonic.....and there's a killer out there who got away with killing her bf 20 years ago, and critically injuring her.
Think of the possibilities? You could bring back all those fan favorites. Mathew Lillard....Skeet Ulrich....Rose McGowan, etc...in cameos. Maybe the one thing they all had in common was that they were friends w/ Drew. And maybe the reason they all come together 20 years later is for a HS reunion.
Ultimately...have the killer end up being a jaw-dropper. Someone famous in the genre. When he (or she) is finally found and killed/unmasked...have it be someone like Jamie Lee Curtis....or Robert Englund. Heck, maybe even a Corey Feldman....or just some kind of random mind-blow, like Keifer Sutherland, Kevin Bacon.....
They could really have a lot of fun with this...and still make it kinda scary. Thoughts?