Is there not going to be a Melody Regular achievement this year? I know that some things take a bit to get going but I thought that since this one starts right on day one and practically right at midnight that the achievement would have been added right away as well.

I can't double check because I can't go that far back on my phone, but what I THINK I remember from last year is that the achievement wasn't added until the 2nd or 3rd day, but had actually been counting since day 1. So, since the Melody Regular achievement is normally the method by which to get I would personally assume that it will be activated, and therefore people should be active all throughout December at Melody's Cottage.

It might be like last year where they put it up after the event started, so sit tight. They might be working on it. :D

Like the others have mentioned, it has been released later on in the past. Whether you visit or not is always documented, there just isn't an official title to see yet :)

The achievement has been added. Visit the achievement page, its the first one.