Currently, the truncation of the change streams pre-images collection is marked as exempt from the ticketing system due to concerns about memory usage if the task doesn't proceed. However, similar tasks (range deletions and TTL deletions) are marked as background priority. This ticket is to investigate whether the priority of this task should actually be exempt or if it should also be a background level task.

After investigation we decided that the priority should be background (based on the input from former stakeholders and this guideline), so the task is to mark the operation as background.

After more consideration we will mark the task as non-deprioritizable as with this we can keep up the pace with user writes that generate new entries in the preimage collection.