Updating Android is a complicated process which in some rare cases can brick your phone. That's why less frequent OS upgrades could be seen as a benefit of unlocked phones. However, security patches are key to keeping your handset free of flaws like Stagefright, which allows malware in via multimedia messages.
Carrier-locked Android devices started getting their Android Nougat upgrades last November, which left unlocked Galaxy devices lacking up-to-date security. Monthly updates should put any apprehension to rest and keep your unlocked Galaxy devices safer.
Samsung confirmed the new release schedule in an email to ZDNet, saying that the March security update will come "soon," though it's unclear on exactly when, or whether that update will include Nougat. As the Galaxy S8 is due this month, it's good to see Samsung commit to protecting all its customers.