No. This is not webview, this is opening a full Safari browser instance and disregarding the user's default browser setting. It also used to be the case with doing a dictionary look up anywhere in iOS too, where the user selects a word, uses the popup menu to Loop Up, and then selects Search Web. This resulted in the absurd situation where you're using your default browser, looking up a word, selecting Search Web and then having Safari (again, not the default browser) open with a search query. Thankfully, at least that behavior has changed recently