The video clearly sets up that if Gwen does indeed appear in Spider-Man: Homecoming 2, not only will she be one of Peter’s high school classmates, but she’s also known him for a while, as opposed to them having just met.
This begs the question of why she wasn’t in Spider-Man: Homecoming, though it’s possible that Peter and Gwen knew each other when they were younger, she moved away and now she’s back in town.
At least one Gwen Stacy audition video was already floating around the interwebs, but a new one comes from Vimeo user Iris Haller, whose scenes include Gwen speaking with Peter Parker (as can be discerned by her offering condolences about a certain uncle) and speaking with her father, police officer George Stacy about her romantic struggles.