Resources in the Catalyst Cloud Metrics Service that have not had any measures published to them for at least 30 days now automatically have their “ended at” timestamp set, to reflect the fact they they have either been deleted or been inactive for that amount of time.
This helps to improve the performance of queries for active resources by reducing the amount of resources being counted as “active” to only ones that have recently had measures published. This is relevant in the rare case that delete notifications are missed (causing the resource in the Metrics Service to not be updated accordingly), or for resource types that are not automatically marked as deleted (for more information, see the FAQ).