WPT details: https://wpt.fyi/results/speculation-rules/prefetch/redirect-url.sub.https.html?label=master&label=experimental&aligned&q=speculation-rules%2Fprefetch%2Fredirect (not currently passing because this is disabled)
Today, Chromium does not follow redirects when prefetching for navigation (most notably from speculation rules). With this change, it will follow redirects, even cross-origin and cross-site redirects. This is consistent with following redirects during other kinds of fetches, though additional privacy constraints apply to cross-site navigational prefetches.