Please, make it USB-C
It'll cause some initial grumbling, but I'm not sure it would be a terribly thing. As well as making waterproofing easier, little sockets at the bottom of phones always seem to collect lint in my pockets, which ends up causing dodgy connections.
What would the EU do in this case?
Fine Apple for not following its regulation, of course. Classic EU.
It would cause an absolute uproar. No iPhones because the EU doesn't like the Lightning port? The argument won't stand a moment's scrutiny and within a week, individual governments will be so averse to the controversy that the EU would be forced to fold.
EU is a huge market for Apple they can't just ignore it. If they are compelled to comply then they could make a EU version of the iPhone with USB-C connector. It would require a bit of re-engineering and re-tooling, but nothing Apple couldn't handle. However I suppose that if this ever happens there will be a lot of grey market export.
Personally with USB-C I don't really mind one way or another.
Windows might be more "strategic" than iPhone, but unlike Windows the iPhone is a product consumers actually want. It won't fly to tell their citizens they can't have it because it uses a plug everyone already has ten spare cables for.
In the long run people will have more spare usb-c cables than lightning ones as well.
Good luck with that.
Normal people don't talk like that about connector sockets.
When you've spent a long time dealing with blindingly or subtly hateful plugs and sockets, a connector like lightning seems utterly magical. I appreciate its ergonomics every time I plug my phone in.
This is not how talking works.
Not to mention what a hassle it is to find someone to borrow their cable from if I accidentally left mine at home.
(Even in the former case, there'd be a much stronger "stifling innovation" case if you're proposing a fully-wireless device rather than just a slightly thinner incompatible socket).
The "debugging apps" case doesn't entirely convince me, either. Unless you're pushing it pretty hard, I'm fairly certain an iPhone will make it through the day on one charge. If not, drop it on a charging mat when you go for lunch. (note that recent versions of Xcode can deploy and debug iPhone apps over Wi-fi -- so the cable isn't really needed for data any more...)
But for those who do need this, it's pretty easy to imagine a case with some charging coils embedded in the back.
My phone is a bit on the older side and has took a beating. My iPad would drain after less than an hour of PUBG were it not plugged in.
If Apple goes pocketless, putting a USB socket on the charging platform is a no brainer. Lightning is much smarter and does a lot more than charging, which is not needed for this.