Disney seems to think so. Park hours go to maximum on March 15. Traditionally March 15-April 15 is Spring Break season and it is pretty crowded. Use good strategies and it can still be fun.
Yes it will be busy. We went last year during that exact time and it was definitely busy, but not unbearable. Some parts of AZ are on Spring Break already then and I know it is for some other states as well.
Those are our DL dates as well. We're going to make the best of it, no matter what. From everything I've read, there really aren't any slow times unless it's pouring rain.
We go every year for springbreak. I think that is not quite as busy as Christmas or Thanksgiving. I think it can be busier in the summer months as well. I think it is because not every school district takes the exact same days for Spring Break. We will be there Mar 28 thru Apr 2