I have absolutely no way of verifying or disproving this idea, but it seems pretty obvious to me that Facebook has a grief metric that they plugged into whether or not to assume someone is dead.
Something like “if more than X% of your friends are saying things that evaluate as intensely grieving, we can assume you’re dead.”
So it’s unsurprising that a lot of progressive people’s loved ones suddenly seemed, from that perspective, dead after Trump started announcing cabinet appointments.
