Apple has updated its Developer Page (https://developer.apple.com/news/?id=01212020a) regarding app updates for HTML5 apps.
Apple says: “The App Store Review Guidelines are designed to help developers create apps that are secure, high-quality, reliable, and that respect user privacy. In order to ensure this, we’ve always specified that all apps be self-contained bundles. This means that the core features and functionality of the app must be contained within the software’s binary, rather than made possible by referring users outside of the approved app — including through the use of HTML5. Apps that dynamically provide core features and functionality with web technology like HTML5 are best delivered through Safari, rather than through the curated App Store.”