If you mean "gone" as into the afterlife or your leave your job, then adding co-owners does not mean they will continue to run. Once your company closes out your account, your flows will stop working since they run on your account credentials. However, it will allow one of the co-owners to update the connections to use their credentials instead.
If you are using solutions, then it is supposed to be much easier to update connection credentials (I haven't tried this yet). You can read more at Connection references in solutions - Power Apps | Microsoft Docs.
Of course, updating the credentials in a flow does not guarantee that it will still work. The credentials replacing your credentials must have the same access that you do. For example, I have a few flows that add events to shared calendars. If one of my co-owners were to update one of these flows with their credentials, they would be able to update the Office 365 Outlook connection, but the workflow would still error out because they don't have the necessary permissions in the shared calendar to add/modify events. So you need to keep things like this in mind as well.
