Because, as that post you pointed out says, he clicked a link. That will open a web browser. They can embed links in the content and the app will open a browser

Because, as that post you pointed out says, he clicked a link. That will open a web browser. They can embed links in the content and the app will open a browser just like most apps. To clarify even further: We used a custom URL scheme that could signal that the content was local. Then they could also use a regular web address if they wanted.