Awesome that you're adding another pack to your Youtube Channel. I think Willlem would appreciate you for selecting a pack of his.
Also there are still alot of new format packs that can be added to the channel, especially ones that have been around awhile(just as World Tour). Maybe down the road your United one can be added
for the ranks beyond the 1st(as you already have the Pacifism rank there). I know this may be in the future though as it's still being played(resolved by Kaywhyn).
Also there are are some packs that need to have replays for (ie Casual lemmings, Colorful Arty's new skills Reverse lemmings, Newly Converted new formats Vamprince Lemmings)