During 2022, the Power Query M Language Specification received seven substantiative revisions (beyond typo fixes, formatting tweaks, and the such). Each brought clarification to ambiguous points or corrected cases where the specification did not align with actual mashup engine behavior. None of the revisions added new language functionality or otherwise resulted in the mashup engine changing.
Interestingly, while the M language gained two new features last year (
catch and structured error messages), neither of these has yet to make it into the language spec.