I was wondering when levels such as tropical wilds collect treasure and defeat enemies would be added. I would like to submit a run for those.

They use a different website ( http://chr.mn/pik4/30 ) for the ILs

In addition to chr.mn that LPhantom mentioned, there are also categories for Collect Treasure, Battle Enemies, and Defeat Bosses RTAs on the main Pikmin 3 Deluxe board (i.e. play through all of Row 1 in a row)

Is it unlikely that IL's are ever added on this sight?

As I said, ILs are on chr.mn. That site is better suited for score-based ILs anyway. There's a link to it in the sidebar of Pikmin 3 Deluxe.