If you search online for historical DL hours, there are a couple of places where the info exists. This site is one of them. I'd check hours for 2022, 2019 and 2018. Also, make sure to check when Easter was each year and maybe local spring break since those fluctuate each year.
Even though DL won't post hours and entertainment until about 6 weeks out, there is one trick you can use. Once it gets to be 60 days out from your dates, you can look up dining reservations for Fantasmic and WOC packages. If they are selling them at 60 days for the dates you're checking, it's almost a certainty the shows will appear on the entertainment calendar.
I did just see that the Mark Twain is scheduled for a refurb in April, which might mean Fantasmic is impacted. I do know they have an alternate ending to Fantasmic they can use when the Mark Twain is down for refurb (not true for the Columbia).