I don't think that would be a good solution, you'd have yet another oddball charging widget and if you didn't bring it with you everywhere the battery would die and you couldn't recharge it.
If anything, I'd rather they put the charging hardware in the front bezel somewhere, since that's already flat. Not a good place for storage or for charging the pencil while the iPad is in use, but at least you wouldn't get stranded with a dead stylus and no charging gizmo.
That depends where your "everywhere" is. I (like a lot of people) work at the same desk every day, and I trust the battery would last if I brought the device home or to a conference or something. Or I could get/bring a spare charge dock.
Charging daily works until you forget to charge it one day at home, bring it in to work, and it dies before lunch. Or the other way if you keep the charger at work, forget to charge it one day, and it dies that evening at home.
I have a second Apple Watch charger at work (albeit a cheaper 3rd party one) for that exact reason. I don't typically need it, but if I forget to charge the watch some evening and realize that it's at 10% when I get to work the next morning, backup charger is handy. Wouldn't want to lose this Move streak!
Sure, I could get a spare charger for a second-gen Pencil too, but it would be a downgrade from the first-gen Lightning charging which doesn't need anything extra.
If anything, I'd rather they put the charging hardware in the front bezel somewhere, since that's already flat. Not a good place for storage or for charging the pencil while the iPad is in use, but at least you wouldn't get stranded with a dead stylus and no charging gizmo.