This absolutely can happen to stable projects. This has happened with Mastodon many times, and Mastodon has been stable for years.
It also has happened with Nextcloud many times, and again, Nextcloud has been stable for years.
It’s not a stability thing, it’s an automation thing. We as devs can only automate so much. At a certain point, it becomes up to you, as the administrator, to manually change things. Things like infrastructure changes, and database migrations, where the potential downtime if we automate it is something we need to consider.