As of today the Galaxy S7 and S7 edge have been removed from Samsung’s update schedule and will no longer receive security updates. What does this mean for you?
Samsung update policy

Before the Galaxy S7 and S7 edge, Samsung would typically support their flagships for three years. During these three years the phone would get two major OS upgrades and monthly security patches all the way through.
After these three years were up, the phone would be removed from the schedule completely. This would mean no more OS updates. Although Samsung did quietly release a few updates for the S6 throughout 2018 after support ended, they were rare and only released if necessary.
With the S7, we expected the same. But things changed when the S7 was moved to a quarterly schedule when it was expected to be removed.
S7 updates throughout 2019

At one point in August Samsung moved it to the ‘other regular updates’ schedule for a while but then moved it back to quarterly updates for some reason.
The S7 and S7 edge are the first Samsung phones to get four years of software support, with the S8 and S8+ hopefully following throughout this year.
Support now over for the Galaxy S7

Security updates are crucial for security purposes and without them your phone could be more at risk of malware.
What should I do?

Samsung do trade-ins allowing you to trade your existing phone in to get a discount on a newer one. You can read more about it here. It not only saves money but is good for the environment as well.
However, due to the coronavirus pandemic, you probably won’t be able to trade in right now, so you may have to hold onto your S7 or S7 edge for another few months.