Chrome is running experiments that will make it possible for a user to install any website as an app from the Chrome overflow menu. Promotion of install (in the omnibox or a Chrome banner) will remain limited to websites that use the beforeinstallprompt event or when other install promotability criteria is met.
If you have feedback about this changes, the team would like to hear it. Please be courteous and base your feedback from the assumption that the goal is to improve web experiences.