No, the Swift project was started in 2010, it was only released in 2014, and it was new to most of Apple at that time. Apple didn't start shipping things built

No, the Swift project was started in 2010, it was only released in 2014, and it was new to most of Apple at that time. Apple didn't start shipping things built with Swift until 2015, and even then it was only a tiny proportion of their software. Even today, the vast majority of their software is Objective-C, because Apple aren't just going to rewrite everything in Swift just because.