I doubt development on U4 DLC began 1.5 years before U4 was released.
Lots of stuff there that never turned into anything. Such as...
10. Japanese new IP which is set in...Japan. Third person action adventure title with monsters and machines. Might have RPG elements, not too sure on that unfortunately. Futurisitic setting. Playstation exclusive.
No but they could have assigned some people to prototype ideas for their next game. Didn't they only went "full" production on ULL after UC4 development wraped up?
Also for the #10... the only game that pops to my mind when I read the description is Let It Die, which fits the bill.