As much as I normally hate TWC's stupid decisions, this one isn't entirely surprising. If they're seriously resorting to having no live programming on Thanksgiving, then viewership in the last couple years has likely been very low. Cable TV’s viewership as a whole continues to decline, and while there will be plenty of people watching TWC on the days leading up to and after Thanksgiving, nobody is really watching on Thanksgiving day itself.
I wouldn’t be surprised if other channels start doing this as well in the future. People these days are looking to save money wherever they can, and if they can do so by not paying meteorologists to work on a day with a very limited audience, they will do that. As much as I hate to say this, I’m surprised they didn’t start doing this years ago. On the other hand, if Thanksgiving ends up being a highly active weather day and they don’t cover it, that’ll be a different story and one to be upset about. If the day ends up quiet, I see little reason to be upset about this. TWC has been on the air for us on the daily for decades, and missing one day so most of the staff can spend time with their families I don't think is much to be angry about.