I would like to believe that, but my gut says otherwise. It doesn’t seem realistic that a business of WDW’s maturity and resources would not have a plan for surge staffing. For what it’s worth, though, conversations with cast members seem to indicate that the short staffing is a chronic problem that’s affecting morale. There was also a suggestion that January and February are high absentee time periods due to cast members burning up their sick leave for the year. (Seems odd for a company to drop an entire year’s sick leave at the first of the year instead of incremental by pay period, but that’s just my non-Disney experience.) I can’t testify to the truth of any of it, but it tracks with my observations. The mere fact that cast members are willing to have those types of conversations is worth noting. There was a time when such conversations between on-stage cast members and guest would have been unheard of.
I have a trip coming up Apr 24-May 5. In close to a dozen trips over two decades (never during a busy season) I’ve yet to have a predicted or actual crowd level 1 day at MK. There is one at least predicted now. Hoping it will be true, just to see what it is like! Touring plan generator says not to bother with FPPs! 
I still will. I visited during one of the other “surprize crowds” periods in late 2015 where the actual crowds refused to follow the predictions. Crowds were generally 2-4 levels above predictions, but all was still fine with the touring plans.
will
Just remember that the numerical system for crowd levels is being tweaked. If I understand correctly, they are reassigning numbers to ensure that there ARE actually "1"s, as well as 2s, 3s, etc. This means that the “1” you may see on your trip is probably closer to what a “2” or “3” used to be. In any event, it is still the lowest anticipated crowd, given new conditions, and that is amazing! Congrats!
rebeecky:
When the longest predicted wait for any ride the entire day is 13 minutes (including headliners), if the actual day comes even close to that, it is going to be a great day. It is the day I’m going to be looping my son’s favorite rides for as long as he can take it. We’ll see what comes first, him or me yelling “uncle” or the park closing. My wife will likely abandon us earlier with an eye-roll.
will
That sounds like my kind of trip!
Sorry if I missed it elsewhere, but we’re the stats guys able to come up with anything?
Stat Guy Here! 
The reason Easter is important to the crowd calendar is that many school systems schedule their spring breaks to the week ending on Easter. For these families, Easter Sunday is a travel day. This is why the historic crowd levels shows Easter Sunday as having moderate crowd levels.
This year Easter is early. (If you want to understand why Easter dates change and to see the range of dates take a look at Wikipedia.) This causes the spring break season to be compressed. This year 80% of the school districts we follow will have their spring breaks either the week of Easter or the week after. The week after Easter is going to be just as crowded and Easter week. This will dampen the effect of Easter being a travel day.
Being a Statistician, I want to trust the models. My gut makes me think that we are going to see a lot of 8s, 9s, and 10s between March 26, and April 8. 2016 was the last time Easter was Early. (March 27) Looking at the Historic Crowd Levels, there was a slight lull during Easter Weekend.
Bottom line: Easter Sunday is going to busy!
Arrive early, use a Touring Plan, and re-optimize often. This will keep you ahead of the crowds.
Thanks. Fortunately I’ve always avoided WDW like the plague during spring break, with some padding on either end of it just to be safe. Where I got caught off guard was Mardi Gras week this year. I’m always prepared for the crowds to be a little heavier than predicted, but this was the first time a 5 ever turned into a 10 on me (and coincidentally, the first crowd level 10 I’ve ever experienced). I found out I was right to avoid the 8-10 levels all these years, but I can’t help but wonder where a stitch or two may have been dropped in predictions. I’m inclined to believe your models are tighter than a five point swing would suggest. Did something unpredictable happen that week?
We thought there were significantly fewer cast members in February as well.
One cast member, however, was going on about the $1000 bonus every employee is going to get and I think she said the payout was in March. She claimed nobody was going to quit before then and that new hires would be on hold (not my words) until after this payout. I have absolutely no idea if any of this was true, and it got a little old so I kind of tuned her out, but I’m curious if anyone else has insight to such claims?
With what @paulleewatkins was told about cast members using up sick days… and maybe some of those cast members planning to bail after a bonus… well, I could see them using up days before the bonus is issued.