Sorry, I forgot to put different as well. I mean, futuristic too as well as different, because I think the architecture we see outside of the Abstergo building window as well as the interiors in AC 1 and AC2 all seem sleeker. The design of the settings I've seen Desmond and his team in, made me think it was later than the year 2012.
The animus, with how the beginning of AC2 played out, doesn't seem like such a self contained thing. Those things seem to be mass produced, which we could read into as well.
Plus, I remember the emails we got to hack in AC1 depicted a different America and a different world. The President of Mexico was ramping up border security to keep out all of the American refugees trying to get out of the U.S., one email about the final film studio in the country closing down.
So, I'm pretty sure a Desmond game could and probably would have buildings and a city that would look different than ours in some ways atleast. It'd be more interesting than something that looks like a modern New York. We had inFAMOUS do that already, I think.