Yep, can't say I have really heard it before. The human voice is truly a gift, haven't got a clue what they are singing about but I can certainly feel it.
Better quality version:
https://youtu.be/FkvGAiyPw-E
The top national anthems that I personally hear as inspirational arethe Brazil, Italy, France, Wales. Scotland and Russia ones.
If our national anthem was grooved up with a faster tempo it would be ok
Below makes it sound quite good in dubstep.
https://youtu.be/LCWOoLpeA-s