These indices shouldn't be closed. This is a result of a not gracefully aborted operation. In a normal situation, we don't have closed indices.
However, given the possibility of the exceptional scenario above, we were expecting ILM to be able to delete and therefore clean up these closed indices, as referenced in Elasticsearch ILM failed delete closed indices - #2 by rtwolfe94022 : "Yes, ILM can delete closed indices"