In https://www.w3.org/WAI/WCAG22/Understanding/understanding-techniques:

W3C's Techniques for WCAG 2.2 document is updated periodically, about twice per year, to cover more current best practices and changes in technologies and tools.

This sentence, especially the phrase "about twice per year," doesn't seem to reflect the actual update cycle.
We know that the WCAG 2.x Backlog Task Force is currently working hard.