My theory on the names, all of them are a stretch, but it kind of makes sense for me to link all the names to abilities somehow if they mean anything???:
Runner: Bolivar goes fast
Plaid: Square-ish rock-hewn churches with their non-adjacency rule could form a plaid-like pattern laid out on multiple tiles of a map
ZoomZoom: Zoom conferences are the envoys of our time. And Teddy doubles them
Tiny Car: I can see some dev imagining the Court Festival and picturing a clown walking out of a tiny car in front of amused Catherine. That or there maybe is a diminutive word play hidden in there.
If so, SoonTM sounds to me like a perfect clue for a nation that is waiting their entire history for something. Perhaps a divine individual of some sort?
(yes, I do realize that it won't happen)
By the way, I think somebody mentioned here (albeit half a year of posts ago) that there was a leak of all the leaders in Civ V back in 2010 before the release, is there any way to learn more about it?