You can sort of tell (if you had not looked up the spoiler) who is to be saved, as I have noticed for the last 2 or 3 weeks, for the camera mainly on the right, it is the first couple they show that is "saved".
For the Central / left camera, they start with the couple at the front, then finish on that couple just before the announcement - and in that case it is the last but one to be shown that is saved.
I found my self saying who was saved each time correctly
I assume they have other "patterns" they use - but they cannot be randomly pointing at couples - the Director knows who is to be announced as "saved" so has to get the shot set up for the closeup.