Sorry about the frustration. Whenever a new update appears, I often choose to not update until my project queue clears out.
If it never clears out (sounds like your case), you have to take a series of actions which can prevent project corruption. These are what I refer to as "editors' rules of thumb," which essentially have not changed for decades. Some thing have not really changed for 30 years. Will they change? Probably not, but I'm hopeful.
When the update comes, find out if it there is a good window of time when upating a version (and any requisite project files) would best be done. You have control over this. Adobe does not decide to update your project (as you suggeted). Do not update until that window opens (between "seasons" or major project workflow redesigns: Productions, for example).
Before updating, ensure you keep old versions installed and adjust Creative Cloud preferences to assure that.
Close all projects, then choose Preferences > Media. Delete all media cache on disk to prevent project corruption.
Open the project(s) you plan to migrate and simplify it (them) as much as possible.
Duplicate the project file(s) you are updating before updating it so that you have a back up.
Ensure you have at least one working backup file (check the Auto Save folder, clean out old unneeded versions)
Sync settings to Creative Cloud.
Open legacy projects via File > Open not by double clicking on them.
When opening legacy projects rename and increment them—do not save over existing projects by "replacing them." In other words, do not destroy original projects. Duplicate them.
If projects do not open, trash preferences.
If updated projects are malfunctioning, create a new project instead, and import the malfunctioning project into the newer one.
If project continue to act up, return to the previous version and complete the project there.
Hope these steps help you - they are from my 1997 NLE course! (Kidding, not kidding) 🙂