In September 2021, Samsung moved the Galaxy Note 9 launched in 2018 to the list to receive quarterly updates. Theoretically, it should have only been updated twice since.
However, over time, the phone has been updated three times in December, January, and February. Now, we have the April update for the Galaxy Note 9, which brings with it the security patch. Android March 2022. Thus, Note 9 received up to four updates in six months.
Currently, the update is only available on Verizon, and T-Mobile, Sprint devices. However, it is likely that other variants will also be updated in the near future. The update for the Galaxy Note 9 carries build number QP1A.190711.020.N960USQS9FVC5.
Considering that Samsung doesn't need to update this nearly four-year-old device as often, it's great to see it continuing to do so.
The Galaxy Note 9 will officially stop supporting updates this fall when it reaches the 4-year mark unless Samsung changes its mind. We know that newer Samsung devices will get 5 years of security updates, but the Note 9 is not on that list.