Yah, unfortunately, WDW doesn’t announce their rehabs too far in advance. Some things will be closed when you are there, Maelstrom and El Rio de Tiempo (or whatever it is called.) Disneyland actually list which ride is going to be closed and for what dates a couple months in advance. I wouldn’t expect anything major to be down during that time. It is a pretty busy time of year, right around Easter, so every thing should be open except those rides that have been either permenantly closed (Journey into your Imagination), or those that are only open seasonally (Carousel of Progress, etc.)
This site keeps track of what is currently closed, or is announced as closing.
Have a great trip.