Over the years, we have done the Easter break at WDW twelve times; we have also done the Christmas break five times. Contrary to what is noted above, park closings can occur during the Easter weeks, but likely you will not face that problem because Easter is late this year in mid-April. The risk of closings has generally been limited to when Easter is during last week of March or first couple days of April. That is the time of the double whammy -- there are a huge number of schools that always have either the week leading up to Easter or Easter week as their spring break, and then there is also a fairly large percentage of schools that always have their break last week of March and possibly into early April'
However, that Easter is mid-April does not mean park crowds will be manageable. They will be huge. Easter crowds are not, from our experience, quite as bad as Christmas week. The total crowds at WDW overall might be close to the same both times of year but Easter has the advantage of having both waterparks open and usually temperature warm enough to use them and the resort pools daily, with the result that some of what would otherwise be part of the park crowds daily if it were Christmas, is spending more time at the waterparks and resort pools during the Easter weeks.It is actually the waterparks that have the highest risk of closure as sometimes they stop allowing entries by 11 or 11:30, but then open up agian sometime in latter part of afternoon.
As with any crowds, how bad they really are is ultimately a factor of individual tolerance. You can read through threads like this one and see responses where some guests think the crowds were not bad at all and others swear it was so bad that they will never do it again, and both of those could be talking about the same Easter holiday time. As to reality what you will find is stifling street crowds and very long stand-by lines close to but a little short of Christmas time. Early morning at rope drop till about an hour later is often a time you can hit a couple of attractions without huge lines. Also, keep checking hours including when you get there. Sometimes Disney just opens all the parks an hour early to everyone and does not announce that it is going to do so until during those Easter weeks.
For the Thursday through Monday of Easter weekend, we have found the following. Whatever you do do not go to MK on Easter. Everyone it seems goes there on Easter, with large numbers acting under the impression that something goes on at MK on Easter Sunday that you cannot see other days of the week. But reality is that nothing goes on at MK on Easter that you cannot see other days of the week. Disney does not treat Easter like Christmas. There are decorations, but they are far more subdued than anything you see at Christmas. MK on Monday is also almost as bad as Easter. MK is hugely crowded all days but we have found the Friday before Easter to be a little better than other days. Epcot and AK usually have their lightest days on Easter, with "light" being relative, meaning it is just not quite as hugely crowded as other days. And Saturday is their second best day (possibly because it is a huge travel day with people traveling in or out of Orlando and thus not going to parks that day). Studios is typically crowded all days about the same, and with half the park still in redo mode, it is likley to be horrendous the entire time you are there.
Also be aware as an off-site guest that you can have some fastpass problems that time of year. Having to wait until 30 days out to make FP+ selections could easily mean you will be blocked out from finding many reasonable times available for Seven Dwarfs, Soarin, Frozen ride at Norway, Test Track, and potentially some others.
Note that if you are intending to eat at any WDW restaurant and have not reserved yet, you better search now for any possibilities you may want as all dinner times can disappear. A true story: we had a reservation at Crystal Palace at 5:30 on the Thurssday before Easter. A couple in front of us waiting to do intial check-in approached the booth without a reservation and asked the CM if he could tell them the next avilable time that was open. The CM spent a few minutes staring at his computer and apparently going through reservations. Finally, he looked up and told them, "Tuesday at 9:00 p.m." Sometimes you have to be precise about the questions you ask.