Glassnode provides metrics that can potentially update their numbers historically. Metrics that can change historically are part of so-called entity metrics and exchange metrics (a subset of entity metrics).
Entity metrics can change due to automatically updated clustering information.
Exchange metrics can additionally change due to the manual addition of exchange labels (historical changes to these metrics are rare and are announced on our changelog). You may also be interested in our article on exchange metrics.
Please see here for a full list of our mutable metrics.