That’s sad to hear, but somewhat understandable. If there was going to be a Sinister Six movie, we actually could see it taking shape on the Sony side of things, where the studio has successfully launched its own Spider-Universe with Venom and the in-production Morbius. There are plans underway for stories with Silver Sable and Black Cat, so if a Six feature were to form, it likely would be born from those collaborations.
Article source: https://www.cinemablend.com/news/2471491/are-the-spider-man-movies-building-to-the-sinister-six