I think I know what happened. Not too long after the holiday season start and end dates were first officially announced by the Parks Blog, I checked the
Disneyland Resort website and noticed that they had filled in the holiday entertainment for Downtown Disney (not on the calendar, but just as a synopsis of what would be happening in DTD). Included in that synopsis were carolers and scenes from the Nutcracker.
I remember saying in the Christmas/Holiday Season Superthread -- which is maybe where you saw the Nutcracker reference?? -- that I thought it was very odd that the dates listed for the Nutcracker and for the carolers were the exact same dates as when those events happened last year, without even a shift to one day later on the calendar.
But, since the caroler and Nutcracker info was right there in the description of what was happening in DTD for the holidays (on the DLR website), I thought it must be correct and I added it to my Dates to Remember post on page 1 of my Superthread. I was always suspicious of those dates, though. I had a feeling that this was a case of Disneyland's computer system not having purged the old info from the system yet, and so the old dates were still showing up and someone hastily put them on the website.
I just noticed now that the Nutcracker info is not showing in the Downtown Disney section of the DLR website (at least not in the area where I looked), although there is a reference to carolers in the Winter Village section and in the Yuletide Entertainment section -- so the Nutcracker plans must have changed,
or someone figured out that the dates were old/incorrect and took them down. I'll remove the info from my Dates to Remember post!
ETA: This is the post (from early October) in the previous Superthread in which I was commenting on the dates being exactly the same as they were in 2013, and being puzzled by it --
HERE.