Imagine the pain of selling accessories for two types of iPhones, USB-C and Lighting. The engineering that needs to accomodate two ports. The amount of people turning to the grey market to get a USB-C iPhone.
I'd be shocked if Apple ever releases two models. My bet is the first iPhone that falls under the European mandate will have no ports.
I'd give that maybe a 75% chance. I'm not totally sure they're quite ready to release a portless iPhone, which I believe would be a very unpopular change overall. Angering users hasn't always been a big concern for Apple, but I think it's more of a concern than it used to be. Wireless charging just isn't a good fit for a lot of charging scenarios.
Selfishly, I do hope that they don't release a portless iPhone anytime soon. I'd have to choose between upgrading my iPhone -- something I do every year or two -- and having CarPlay work in my car (which needless to say I very infrequently upgrade). I suppose a dongle or attachment for this purpose would be inevitable.
And the amount of people turning to the gray market to get a Lightning iPhone. I personally live in the EU, and I'll strongly consider importing my new phone if Apple decides to go with two separate models.