This is revisionist history. For Apple to be heading this way "all along" they would have needed to start making Lightning device transitions BEFORE the EU regulation ever got proposed. The transitions of the last couple of years has only happened AFTER the EU regulations passed.
Yes, a pre-regulation transition would prove the point, but the
lack of one doesn't
disprove anything.
Its impossible to know the cause-and-effect of this unless you've got an inside line to Apple's thinking.
Putting the M1 chip in the iPad Pro gave it the potential to support Thunderbolt, 6k displays and full USB 3.x - which are beyond what Lightning can do (Lightning can't even do USB 3 without an active dongle). They're pushing iPad Pro as a Mac alternative, so it starts to make sense for it to be able to use the same USB-C accessories as the Mac. The power requirements were going up, too. So there was a good argument for making the iPad Pro USB-C - EU or not - and at that point it starts to make good sense to standardise on USB-C as the standard charging connector. The media creation potential of top-end iPhones is going to have them outgrowing the bandwidth of Lightning soon, if not this year.
Maybe the upcoming EU directive was a factor in why Apple didn't develop "Lightning 2" to preserve their lock-in rather than go with USB-C - in which case, frankly, that's the EU directive supporting consumer choice as intended.
But Apple wasn't pushing that mandate to happen.
I don't think that was ever a serious possibility. Just that Apple would be "briar patching" if they complained too hard about the EU directive - Lightning was approaching end-of-life anyway and many customers
will doubtless by new Apple-branded accessories rather than exercising their right to shop around. I'm not sure if Apple themselves have even said that - I just see a lot of vicarious complaints on their behalf.
It was mini-DP and USB-A that were the targets that Apple was keen to move off the board.
That went well - 7 years later and this year's model Mac Mini and Studio still have USB-A ports & they've
re-introduced HDMI and MacSafe to the MacBook pro...
A big factor in Apple going with USB-C must have been Intel's decision to make Thunderbolt 3 use the USB-C connector, and we'll never know whether that decision was influenced by Apple. To me, that sounds like an Intel decision - betting on USB-C rapidly replacing USB-A and making Intel's Thunderbolt controllers the go-to USB-C implementation. Apple had committed to Thunderbolt 1/2 so they pretty much had to add USB-C to the MacBook Pro - and the thing about TB3 is that a small number of fully functional port hoovers up all the I/O resources that could be used for dedicated connectors.
The problem with USB-C is that it always made most sense on a phone/tablet where having a single, tiny, universal port is a near necessity - and it was conceived at the peak of the "why would anybody buy a PC anymore when you can do everything on a tablet/phone?" era.
Whatever
Apple's intention for USB-C was, it was clearly designed with mobile device use as a major factor, and the rest of the industry was always going to see it as a no-brainer replacement for microUSB. The EU provided a helpful disincentive for anybody to think about making their own proprietary microUSB replacement or fast charging standard.
(Of course, the 12" MacBook was the first to go USB-C - but I'm sure that the original plan was for a later model, if there had ever been one, to add Thunderbolt support just as soon as Intel released a suitable CPU with integrated Thunderbolt)