I'm going to wildly speculate.
Coming right after Doomsday puts it in a spot similar to Ant-Man and the Wasp. We'll likely get a film that does its own thing, and then the mid-credits scene will link to Doomsday.
So let's start by having Daredevil:Born Again elect Kingpin as Mayor of New York. As Mayor he outlaws superhero vigilantes. This doesn't actually stop heroes like Daredevil or Spider-Man, but it does set up an anti-superhero sentiment and give JJJ plenty to work with.
Peter wants to be a hero, he's doing a good job, but he keeps getting shit on. He sees stories on the news about heroes in other cities, sees everyone cheering them on, feels bad/is jealous.
Eventually he's hunting down some bad guys and comes across an illegal shipment of weapons or something. Eventually learns an organization known as "The Ten Rings" are responsible, and learns that they have a base of operations in Boston.
Peter misses his friends, even if they don't know who he is. He decides to investigate by leaving New York and going to Boston/MIT. He'll learn quickly that this new city isn't quite designed for Spider-Man, so he'll struggle even further. He'll have a scene where he saves MJ and ends up dumping a lot of personal feelings on her. MJ will be surprised to see a superhero acting like a regular person, but she'll give him some advice and Peter will feel better.
In terms of the bad guys in Boston, it doesn't really matter. Shang Chi should show up at some point investigating The Ten Rings, heck maybe he even solves it without Spider-Man. Then MJ can inspire him. Either way the finale ends up with Spider-Man back in New York and he defeats whomever The Ten Rings were working for. Even if the backup in Boston is already defeated, the main baddie can still be in NYC.
So Spider-Man saves the day. We find him back home looking at the same photo Tony Stark looked at when he decided to invent time travel. Peter is feeling great, says that he did good today Mr Stark.
Then we get our mid credits scene, purple portal like in Spider-Man No Way Home. Out pops Doctor Doom. Spider-Man prepares to fight. Doom says something ominous. Peter, confused, responds "Mr Stark?" and scene.
With that we get our brief friendly neighborhood Spider-Man story. We get some progress with MJ at MIT. And we still get Spider-Man fully involved with the Doomsday multiverse story. After which we can return to friendly neighborhood Spider-Man again (again).