> > The "paragraph" role isn’t mapped to a <p> tag because it’s an HTML conformance error to include block-level children within the [article] element

I believe you are misquoting here. "The element" refers to the paragraph element, meaning that valid HTML5 doesn't allow block-level elements within <p>. This is supported by what follows the quote:

> in React Native for Web both Text and View support block-level children.