If we’re being honest, the characters of Norman and Harry Osborn are ones that should be introduced early, and be developed over time.
Rushing into a conflict between Peter (Holland) and an eventual Norman would be detrimental, so it’s possible that the storyline could be teased in future MCU Spider-Man movies, and developed over time.
I figured that one of the juiciest storylines that Tom Holland his new collaborators at Marvel would want to finally tell their version of would be the Green Goblin, and Norman Osborn.