Wikipedia? Seriously? Are there no government or news agency reports worth linking to? And is this really superior to just having the Foundation notice and say "hey, these all had big massacres happen as of late"?
If you're going to nitpick about linking to Wikipedia, there have been other articles that also does that exact same thing (SCP-2688 and SCP-3872 come into mind).
In my opinion, these in-line links are out-of-universe and serve for the out-of-universe reader's understanding, since some readers express the opinion that they do not understand the significance of those places. I don't see why there would be in-universe link for the SCP articles themselves, since I would perceive them to be isolated files for the sake of security. We (readers) are likely the only ones who will gush and care and react towards cross-referencing, while the "real Foundation" will chalk it at "I am cleared for this. I am not cleared for that".
After all, while they are places where tragedies occurred, they are not as ingrained into the collective psyche of our species as… say, Auschwitz or Nanking (as far as contemporary humans of the more developed world go by).
I really wish there was another way, but this is the only preferable option.
If you're going to write about merfolk using magic arrows to hunt and slaughter these gigantic sneaky death centaurs, I would much rather read that in a tale than try to puzzle it all together from an SCP (only to fail and resort to the comments section anyways).
That portion came in the idea process at the last leg. My intent with this article was from the beginning, always about a train that drowns one to death. The problem lies in why would it happen.
At first, I thought of the "spacesuit" for mer-people analogy. But that does not account why would the breathing thingy go haywire. I could go for "for lolz" route if I have nothing, but that is a meaningless layer of characterisation. The mer-person needs something firmer to be grounded upon.
I then drew parallels with the selkie and merrow, which first introduced the Ogham as text to outright state the "spacesuit" for me-people part. But that was telling, not showing.
And along the way, I decided that SCP-3456 can be thematically suitable (since it's in the North Sea and all). And I went about with the mer-person tracking down an 3456 instance. It provided a situation wherein the mer-person can be in great injury to the point that it will not mind implicating hundreds of lives.
I frankly don't care about "merfolk using magic arrows to hunt and slaughter these gigantic sneaky death centaurs". It's an afterthought, as far as I am concerned.