The bug
The 'What's new?' button in the Settings -> About tab is not shown if Wi-Fi is enabled after the Launcher has been opened. This is inconsistent with other elements of the Launcher, like the Java Edition patch notes and the Play button.
How to reproduce
Open the Minecraft Launcher with your Wi-Fi disabled
Re-enable your Wi-Fi
Click 'Try again' in the grey bar on the bottom (until the bar disappears), and notice how the Play Offline button properly updates to Play
Navigate to Settings -> About, and notice that the 'What's new?' button is missing
Will be fixed in the next release.