Is often enough too often?
Here is my advice to companies. First look at the anticipated change or threats to the QMS (or EMS). I've just started working with a company and I suggested a management review every other week!!!! Just like a baby, new systems require constant attention and resource allocation on the fly.
As the system matures, the management review can slack off (provided the change slows). After registration, the organization could go to quarterly for the first year or so. Once the system is mature and provided there are no threats, then yearly might be okay, but with the level of change we see today, I wouldn’t go much past that. One company I work with has a semi-annual schedule. However, they have a bullet list of about five items that would trigger a management review within 30 days.