If they still do it, the "Easter parade" in the Magic Kingdom was actually a "pre-parade" just ahead of Festival of Fantasy that featured some special Easter/Spring themed floats and characters including the Easter Bunny. We were there for Easter 2016, and though I had researched all of the "Eastery" things going on, we didn't really do or notice any of them. We were in Animal Kingdom on Easter Sunday, and honestly didn't really think about what day it was.
Epcot has (or at least had) a kind of egg hunt thing. There are big eggs with character faces on them "hidden" all around the World Showcase. You can get a map (I think they were $5) and you fill it out with which eggs are in which locations (maybe had stickers to put on the map? I can't remember). Then you bring the completed map back to a shop that sells them and they give you a prize for finding all of the eggs. We didn't do this, I just read about it and have no idea what the prize was.
Flower and Garden is also going on at Epcot during Easter, so there are lots of pretty flowers and topiaries as well as some "Outdoor Kitchen" food kiosks with yummy offerings.
A lot of restaurants do Easter Sunday brunches.
There are even church services in various locations. I think there's one at the Contemporary, and I'm not sure where else.
The closest we got to an Easter experience at AK was nearly seeing an unfortunate bunny rabbit attacked by a mob of savage meerkats. The CM at that habitat gave us a heads up that it was going to be gruesome if/when they got to the rabbit (and they had seen him and were heading his way...very close up to the viewing area...ugh). We left. I hope no unsuspecting, innocent children were traumatized that day by seeing a bunch of Timones violently murdering the Easter Bunny.