We aren't able to highlight this unique content
This is a real euphemism. It sounds like Reddit essentially patched a sinister type of manipulation (deleting posts so only moderator-selected posts remain).
The dropoff if AMA score performance was quite drastic from this change:
I understand the mods frustration that stupid content is more likely to go viral than good science content. However, deleting valid science posts is not an acceptable solution. If there's one main reason I don't use Reddit more is that one's hard work can disappear in a blink.