It looks like the "tid" field isn't in the list of fields to include in the output doc when reading from change collections. Specifically, it looks like the field is filtered out here. This means there will never be a "tid" field when constructing the NamespaceString object.

I hit this when attempting to add an assertion in NamespaceStringUtil::deserialize that a tenantId is always set when multitenancySupport and featureFlagRequireTenantId are enabled running multitenant_read_from_change_collection and basic_read_from_change_collection.js.