I just think it didn't even occur to them...they always write/make props according to the predicted air-date of the episode...so I think they are just keeping with that habit and not even thinking about the actual time passage in the story...

I'm beginning to think my S6 timeline will have to have a "logical" version and an "as seen on the show" version :P It's either that or I just declare there to be two 2010s, like you did...I don't know. Sigh...