The highlighted had me thinking about the characters from the various Scream movies that aren't part of the Big 3 and just how well all of the Scream films (even 3 and 4) did with creating new characters that audiences could relate to and care about.
Everyone loved Tatum in the first Scream so when she got killed it meant something. And all Scream fans sighed with relief when Randy made it out of the first movie alive. Even Kenny the Cameraman was a fleshed out enough character that when he died it wasn't just a throwaway scene. Even Drew Barrymore's death was meaningful because we related to Casey (partly because we were all familiar with Barrymore) because in the brief time she was on the screen she had personality and wasn't just a big boobed bimbo who's sole existence was to get topless, fall down while being chased and die.
In Scream 2, we were introduced to multiple doomed characters played by actors we were familiar with who had emotionally stirring deaths.
Jada Pinkett and Omar Epps dying in the opening scene mattered for two reasons: we were familiar with the actors and in the short time they were onscreen they were fully formed characters and not just thin archetypes.
The same goes for Sarah Michelle Gellar as Cici. True a lot of the audience automatically liked Cici because she was being played by Buffy the Vampire Slayer but Cici was also given a good chase scene (probably the best in the movie) that was reminiscent of Gellar's chase scene in I Know What You Did Last Summer. So when Cici got chucked off the roof it had some emotional heft to it.
And let's not even get started on how big a gut punch Randy's death was in this movie.
Even someone like Hallie (who had such a horrible death scene) ended up being a successful character because she was Sidney's best friend and she mattered.
Jump to Scream 3 where Cotton Weary and his wife are killed in the opener. We were familiar with Cotton but his wife was brand new and her death was almost as sad as Cotton's.
Of the new cast in the main film I would say that Parker Posey, Deon Richmond and Emily Mortimer all created characters who were engaging and made their eventual deaths matter more than Jenny McCarthy did as basically one of the big boobed damsel in distress caricatures I mentioned earlier.
Finally with Scream 4, I would say that the majority of the younger set that was in the movie pulled off being compelling, interesting characters that you would root for, be sad when they died and surprised/disappointed when they were revealed as villains.
So it stands to reason that Scream 5 will feature at least a couple characters (cast with capable enough actors) who will be able to take the baton from Sidney/Gayle/Dewey and run with the franchise into the next generation.