Although "long planned" is this is another example of the "Dynamic Force Employment Model"? I linked a couple of articles here
Baltic BUFFs - Minot - Baltic - Minot
"The transition to a “dynamic force employment” model allows the bombers to operate from a “broader array of overseas locations” with greater resilience, while keeping the aircraft permanently based in the U.S., AFGSC said."
Instead of long-term deployments, the service is currently focusing on sending small groups of bombers on short-notice flights across the globe to be more unpredictable.
So I assume deployments like this one will become more frequent.