That's quite a large loss. Esp. given that there's another option - stay on the EU market while conforming to its rules. That will lower the profits, but not by that much.
Losing Europe as a market would have larger consequences, though. Software produced in EU would have worse support on Apple, people even in US having connections with Europeans would start installing alternative messengers etc. Apple's strength is in its network effect, cutting out a major part of it would be disastrous.