iOS - Trait Collection Events Selectively Called
<p>I have a main view controller with a series of buttons and a content view.  When a button is pressed, all the subviews are removed from the content view, and a new one is loaded. It's essentially a custom tab bar controller with some extra features.</p>

<p>From the top level view controller I am seeing <code>willTransitionToTraitCollection:withTransitionCoordinator:</code> and  <code>traitCollectionDidChange:</code> as expected. I am calling super within both of these methods so that these events are passed to the children and presenting views appropriately.</p>

<p>Only <code>traitCollectionDidChange:</code> is making it to the children view controllers (which are for the nested views). This isn't the end of the world, as I can easily hook into that event, but it is very strange to me that only one of the events is propagating.</p>

<p><strong>Is this the expected behavior, or am I missing something?</strong></p>