The employees are all machine learning engineers with a focus on autonomous vehicles (aka, the current hot shit in machine learning), which means they're probably all making $300k+ per year at the low end. They'll be fine.
But the original point stands. They should be able to get good paying jobs somewhere.
Why would engineers in a highly sought-after field not make that much at Apple?
And your 300k from levels.fyi is not base salary. Base salary is listed as 180k, more in line with reality.
Apple never extended an offer, or an offer was not accepted. Either way, they were not at any point an employee of Apple, or any other company.