@Bund there are some things that work and others that really don't; and Luke Cage and Jessica Jones really don't work at all in either Black Panther 2 or The Marvels (those cameos would be completely unnecessary and while I'm sure we'd love it would probably get a lot of criticism unless there was a totally good reason).
Before I write an entire essay here's my short verdict:
She-Hulk (Daredevil, maybe The Punisher)
Secret Invasion (anybody could show up, possibly Kingpin or really just anybody who they can work into the storyline)
Armor Wars (Kingpin could show up as well,
Ironheart (another good place for these characters
So when will they show up? Aside from Iron Fist, all of the Defenders are really street-level heroes and they will likely show up in street-level shows and films, so for Moon Knight any of these characters are out of the way. For Doctor Strange in the Multiverse of Madness, I am sure we'll get a cameo from one or two Marvel TV characters (I'm betting on Black Bolt from Inhumans for the Illuminati; trust me on this one, if anybody else they'd be from Agents of SHIELD). For that movie I'm counting all of the Netflix characters out.
She-Hulk is when it really gets real. Anybody could show up. I wish I could say that Jessica Jones would be one of those people, but from what it seems Krysten Ritter had a conflict with filming and they ended up replacing her with Matt Murdock (who yes, will suit up as Daredevil). So, we know he'll be around for a good chunk of the series, and because it's practically a street level series anybody could show up - The Punisher has also been reported for She-Hulk so I guess we'll have to see. I feel like Luke Cage and Misty Knight wouldn't come around, and while I could see any other supporting character (most likely one from Daredevil), I'm not so sure about the others. I guess another thing we do know is that Krysten Ritter is going to return someday, though when that will be we'll have to see.
For any of the movies onward from Doctor Strange for a little while, I'm going to have to pass on any of these characters showing up. It doesn't make any sense whatsoever for them to return in a completely cosmic movie (yet) in instances like Thor: Love and Thunder or Guardians of the Galaxy Vol. 3, or for larger-scale at least partly earth-set films like Black Panther: Wakanda Forever, The Marvels, or Ant-Man and the Wasp: Quantumania. Blade, while possible, already could be packed with the knowledge of Black Knight probably returning and the film diving into its own corner, and while anything's possible does it really make sense? The next movies I see any Netflix character coming back is Captain America 4, Deadpool 3, and Shang-Chi 2. Captain America is going to be grounded, just like The Falcon and the Winter Soldier and Hawkeye were, and having Luke Cage, Misty Knight, Daredevil, The Punisher, or Jessica Jones would actually work really well within given parameters (especially either of the first two). Deadpool 3 will be complete madness, so expect anything, and Shang-Chi 2 (and/or the spin-off series) kind of needs to have both Danny Rand and Colleen Wing but don't expect anything from them before 2024.
So what about TV shows. They could fit a character into Ms Marvel easily, but that might be a little weird so I'm going to count that one out. However, for Secret Invasion, Armor Wars, and Ironheart, fitting any of the characters (maybe Kingpin, Jessica Jones, Daredevil, or Luke Cage) could add something else to the storylines. For Secret Invasion, it could turn one of them into Skrulls, or have them help somewhat with whatever problem they might be facing in the series - maybe Kingpin could have been involved with them somehow? For Armor Wars, the plotline really fits well with characters like Jessica Jones, Daredevil, or Luke Cage who could try to help James Rhodes get Stark's tech back, or any of the villains - most likely Kingpin - could be the buyers. Even The Punisher could work his way in. Ironheart is a bit more free in terms of who it would put in as it could be anyone, but a cameo would be a nice touch if that's what the story worked in.
Echo is when it all gets real. We know already that Kingpin AND Daredevil will be big parts of this, and I'm sure they could bring other street level heroes (especially Jessica Jones or Misty Knight) back into the storyline with ease. This show will probably be the gateway for the reported Daredevil revival, likely for 2024 or early 2025, and that could lead to more projects with Luke Cage, Jessica Jones, or The Punisher. We don't know much about what comes after Echo, but thrusting these characters into the spotlight for good can give them more opportunities with shows like What If...?, and with bigger characters and beyond.
Basically, I'm saying that once they're really reintroduced back into the MCU, they can team up with Thor, Captain Marvel, or Spider-Man if Marvel really wants them to. Waiting for She-Hulk, Armor Wars, and Echo is probably the best we can do, because those shows will likely really help them bring in the Netflix Marvel Universe for good, and thrust them back into extreme popularity once again.