I myself have a name like that, i think i got it from trying to recover an old lol account. I have grown fond of my overly long name, will i be able to keep it? Except the overwritting tab-screen of course.
Here is my name: B6287133-520A-4365-80E8-35042D6AC535 #EUW
Heres a screenshot of mine: https://puu.sh/FvhIS/461c64ce05.jpg
It sure is a beautiful name, but I'm not too keen on supporting 36 character names throughout the game so that you can keep it lol