By the way, I just went to listen to Umbral Ultimatum when I realised that the initials are UU. I'm sure everyone else noticed this already, but that's up there with Dave's hair being a bird.
If you're going to attribute poignancy to every song that has the same initials as something else the list would be pretty long.
However if you also consider that the song title contains the word "umbra", which is also part of the chatnames of both UU and uu, then you would have somewhat more of a point.