We are expanding support of lightweight formatting to include additional Markdown syntax features. This includes strikethrough formatting and nested lists. To get started, explore these new options in the formatting toolbar, keyboard shortcuts, or by editing the Markdown syntax directly.
Source: Microsoft.
Fortunately this has already been patched but still, what a fuckup
Jesus fucking christ so the fucking idiots really full on dont even try to test any of the shit they facefuck into 1.4 billion innocent pc’s with every update they release.