A Sinister Six movie seems like the natural end goal for Sony’s Spider-Man Universe, but it isn’t the only option.
Given Venom has already momentarily joined the MCU (at the end of Venom: Let There Be Carnage and Spider-Man: No Way Home) and Vulture was pulled from the MCU to the SSU (in Morbius’ post-credits scene). Given this light relationship, it’s possible the characters could join the MCU full-time via multiverse trickery.
Alternatively, Madame Web set up Peter Parker as well as the titular Madame Web and three future Spider-People. Given the movie takes place in the early 2000s, the timing is right for any of them to become recurring heroes in the SSU’s “present day.” The truth is likely that Sony’s remaining 2024 releases (Kraven the Hunter in August and Venom: The Last Dance in October) will determine which direction the franchise will take. With two bombs in a row for the brand, the path forward may change if an upcoming project doesn’t fix the brand’s critical and financial situation.