I have dynamic pages (e.g. app/blog/[slug]/page.js), which I render statically using:

// This is inside the app/blog/[slug]/page.js
export async function generateStaticParams() {
  let posts = getBlogPosts()?.posts;

  return posts.map((post) => ({
    slug: post.slug,
  }));
}

For those pages, I also have:

// This is also inside the app/blog/[slug]/page.js
export async function generateMetadata({ params }) {
  let post = getBlogPosts()?.posts?.find((post) => post.slug === params.slug);
  if (!post) {
    return;
  }

  let { title, publishedAt: publishedTime, summary: description, image } = post.metadata;
  let ogImage = image ? image : `${baseUrl}/og?title=${encodeURIComponent(title)}`;

  return {
    title,
    description,
    openGraph: {
      title,
      description,
      type: "article",
      publishedTime,
      url: `${baseUrl}/blog/${post.slug}`,
      images: [
        {
          url: ogImage,
        },
      ],
    },
    twitter: {
      card: "summary_large_image",
      title,
      description,
      images: [ogImage],
    },
  };
}

But I am not sure whether the output of generateMetaData is also statically generated or not.
Is it? If no, how to achieve this?