Setting a boundary around when news is read does not mean ignoring difficult events, it means deciding deliberately when to engage with them rather than letting availability dictate the schedule, since a phone that can deliver news at any hour will happily do so at the worst possible one if left unchecked.
A workable boundary is usually specific rather than vague: no news for the first hour after waking, none in the final hour before sleep, or a firm stop after a set amount of time each day. Specific rules tend to hold up under pressure far better than a general intention to cut back.
The point of the boundary is not to know less, since the same stories are usually still read within the boundary, but to prevent news consumption from expanding to fill every spare moment of attention, which is what it tends to do by default without some deliberate limit in place.