Egg Whites in Pie Dough for Pecan Pie?

So I'm making pecan pie for Thanksgiving this year (first time making it, I usually do pumpkin for Thanksgiving). Have been looking at the CI recipe and noticed that it calls for a pie dough that has an egg white in it in place of some of the water (one egg white + cold water to reach 1/4 c). I was initially planning on just doing an all-butter crust, which is my normal approach. I found it interesting that this recipe goes along with the pecan pie, though, and I couldn't find an explanation for it in the instructions. I am assuming it will help keep the dough from getting soggy, since they recommend par-baking the crust before filling? They also use confectioner's sugar in place of granulated.

Any thoughts on these subs? Worth doing? A lot of other recipes call for standard dough, so I'm sure I'll be fine either way. Just wanted to get some feedback from Chowhounders!