I think it’s within the realm of possibility, but I wouldn’t say it’s likely (didn’t know what to vote).
If it happened, the current Pencil might be compatible but Apple would probably make a mini Pencil just for the phone. Ideally it would be able to dock inside the phone like the Samsung pen, but it wouldn’t be able to because the Pencil uses bluetooth tech and therefore has a battery therefore making it too big. It would have to dock on the exterior (possibly in a phone case) or not docked at all, just loose in the pocket. But even if Apple changed the pen tech to be battery-less (which is unlikely because they’d either have to pay Wacom to license the tech or come up with their own tech which is apparently very hard), I‘m pretty certain they wouldn’t want to give up any space inside the iPhone for an optional accessory.
The reason I say it’s possible is:
- It seems useful to some people (I have no idea what percentage)
- It wasn‘t clear if Apple was against styluses being necessary or even just as an option—but either way, that sentiment was expressed long ago, so they might not care as much now.
- Apple seems to be more flexible with their design principles these days, opting for more function.
- Apple may be running out of features to add to the iPhone.
The reason I say not likely is:
- Apple might still be really against any stylus on a phone.
- My guess would be it’s not a big enough market to make Apple consider it.
- If the pen tech remains battery-powered, docking/charging would be awkward. I’m pretty sure the main method of charging would be from the phone, not a wall outlet, but it can’t attach to the side of the phone because it would get in the way of holding the phone. It could attach to the top but it would probably stick out on the sides which would look bad and make it fall off when putting it in the pocket. Maybe it could plug in the lightning port like OG Pencil but that was also awkward, plus there’s rumor of Apple eventually removing the port, and that would mean the Pencil would have to stay loose in the pocket which doesn’t seem like something Apple would want.
- A battery-less pen being thinner and not needing to charge opens up more options for storage. I could see Apple selling a case that has a slip in pocket for the pen. However, like I said, Wacom seems to have cornered the battery-less pen market, and I don’t see Apple wanting to pay for the license. But even if they did, it would be weird for the iPhone and iPad to have different pen tech with no inter-compatibility. And battery-less is much more convenient so there would be a lot of customers clamoring for iPad to adopt the same tech, but I don’t see Apple making that switch.