In a vacuum, sure. In practice, that forces the mod to do research on every batshit claim that's commented/posted and opens the doors to just gish-galloping the mod team. You mentioned the citations being more common in the past? This is most likely why. We also just got out of a nasty election in the US, and misinformation and wild clams were running wild. Mods are volunteers and have lives and can't fact check every foreign influence bot and misinformed lemming. Would love to, but, again, volunteer with a life. Sometimes you gotta shoot from the hip when wild claims are made, and if it's pointed out later that's actually correct, then it's not uncommon to see comments restored.
I'm also in favor of modding first and restoring later if need be. "A lie can travel halfway around the world before the truth can lace its boots" and all that.
I'm in favor of the opposite: If someone makes a wild claim, they should be citing credible sources to back them up.