Reviewing documentation for Editable_If, below is the described scope:
The Editable_If column constraint only affects the user's access to the column value, such as when the user interacts with a form view containing the column. The constraint is also checked before allowing access to Quick Edit columns, such as in detail and table views. Editable_If does not affect the application of app formulas and initial values, the performance of actions, or any other app behaviors.
This meshes with my person expectation of when Editable_If is applied.
However, when I run a Report rule to change the value of a column, the change is prevented with the following error message:
"Action Name": "Update Escalation Column", "Errors": "Error: Perform DataAction 'Escalated to Level1' failed because Row having key 'a77b7788 : ffa97ab0: 5fca42e8' in table 'Activities' in field 'Status' 'Editable_If' condition returned 'false'.",