Welcome to MODX. Your question is very clear.
There’s no way to make MODX magically realize that a link should suddenly point to a different page, but there are ways to mitigate and/or prevent the damage.
First of all, you can use the security system to make sure that certain people can’t delete important pages. If you had put resource 22 into a Resource Group, and connected that Resource Group to the Administrator User Group with a Resource Group Access ACL entry, no one outside of the Administrator group could see, edit, or delete that resource. (And, imo, membership in the Administrator group should be reserved for high-level administrators).
Another, not so secure, method would be to create a TV or a System Setting that stores the ID of the page (22). I would use a System Setting called
privacy_page with a value of 22. Then, when you need a link to it you’d do something like this:
That’s a System Setting tag (
[[++setting_name]]) inside a link tag (
When MODX processes the tag,
[[++privacy_page]] will be replaced by the value of that setting (e.g., 22). Leaving the tag looking like this:
The link tag,
[[~22]], will be replaced by the URL of page 22.
Now, when the page changes, you just need to change the value of the
privacy_page System Setting.