Dev Tools wants to be notified about all changes in the explain format. To make sure none of such changes get pass unnoticed, they suggested to create a test which would validate explain output for various query plans. The idea is to cover all possible plans that we can generate. I'm not sure whether it would be feasible at all to come up with such a test, and then support it. This idea also is not quite aligned with our approach to testing explain, since we're validating only specific parts of the output for certain type of queries, rather than checking the entire output. We need to investigate and decide whether such a test would be beneficial.