You're presupposing they would have 1) done it anyway and 2) at the same time it actually happened. They may have reconsidered their attack or delayed it. The delay could have given opportunity for the dynamics to change.

Arresting journalists from a huge news company would come with some blowback. The internal weighing of that potential blowback and how it affects the regime's relations could have changed things. At the very least, it complicates things for them further - stalling them, making them waste time on listening and responding and managing the media to craft the narrative.