There are still some pretty essential Spider-Man characters that the MCU has yet to introduce, but Spider-Man 4 seems like the perfect time to do it. As of now, the MCU Spider-Man movies have split their attention between Peter Parker's personal life and the wider Marvel universe. Following Doctor Strange's spell in Spider-Man: No Way Home, the Avengers have forgotten about Spider-Man, so he is perfectly positioned to have an adventure without their interference. This has led to some speculation that Marvel will include some fan favorite characters, specifically Harry Osborn and Gwen Stacy.
https://screenrant.com/spider-man-4-spider-man-characters-mcu-marvel-theory/