June 2021 my monthly Charts Ultimate subscription ended. (I had 2 months). The default MSFS 2020 Airac updates did not show up after Navigraph subscription ended for at least 6 months before I just renewed back on a monthly Ultimate subscription. Prior to having Navigraph Microsoft MSFS updated the Airac monthly. This is show by loading any airplane in MSFS and checking the Airac dates, such as the Airbus A320neo FMS showed Airac date of July 2021.
The Navigraph AIRAC data for MSFS is an alternative and more comprehensive dataset. If you cease your Navigraph Subscription then the Navigraph data will remain but not updated.
If you wish to revert to the MS/ASOBO data at that point, you should press Remove Navigraph AIRAC Cycle in the latest Navigraph Navdata Center.