But like we all know it's a bluff so there's really no risk. If the EU regulators could successfully kick Apple out without massive backlash from their own citizens it would be a win. The vacuum Apple would leave behind would be massive and give a chance, albeit maybe a small one given Google and Samsung would pounce, for EU companies to fill.
As much as it would suck personally if the internet got partitioned by political region, China absolutely got this one right by kicking out foreign companies that don't bend the knee to let their own domestic industry flourish.
This goes beyond phones, maybe this would be the opportunity as well, starting with something like the Pi, to have the European consumer electronics being based again home made hardware and OSes, like up to the early 1990's, gotta lose our dependency on US computer brands, specially if the government turns yet again.
For starters, the US' own government has also launched an anticompetitive inquiry into Apple's behavior. It's ongoing as we speak, and by the looks of it Apple isn't behaving like a company with nothing to hide.
And Google’s newly declared monopoly threatens to stop the 20B a year in basically free money they paid Apple to have Google be the default search provider. That 20B is 25% of services profits IIRC …
The risk with Apple calling the EU's "bluff" is that the EU may then to seek to break Apple apart into hardware and software divisions, and Apple will have handed the EU the ammunition they need to guarantee it happens.
But Apple's corporate tax structure requires them to be in the EU. It's not just the loss of EU revenues at stake; Apple would owe hundreds of billions more in taxes each year as a result of this "simple" suggestion.