They usually announce that with the Holiday announcement each year. There wasn't even a peep this year, which is too bad. Nothing like legs breaking and ankles twisting to make walking around DL more magical! JK. I actually did like them having that up. It made it more Christmas-ee.
I've also not heard anything about Frozen Fun. They had that back in late 2015/early 2016 and we got to catch it. Then in Nov 2016, they opened Olaf's Snow Fest again. I'm not sure if any of this is happening this Christmas season. That was one of my kid's favorite areas. Perfect place to just take a break from everything and play in the snow. But as it seems lately, pay more and get less of everything....well, less of everything except crowds.