#4 It would help to give birth to new stars

WWE is clearly high on Mandy Rose (and hopefully that's not just because she's easy on the eye). Sonya Deville, also, has a lot of raw potential. Though they would be secondary players in this particular drama, being involved in a prominent WrestleMania program would certainly help to elevate the two of them, getting them exposure and experience at WWE's highest level.
Eventually, when Paige's stable breaks up, they'll be in a better position as they go their own separate ways.
Cody has no chance against John Cena? Details HERE
With this element also added, Paige vs. Asuka at WrestleMania is smart booking both for this upcoming season and the long-term future of WWE's women's division.
Here's hoping that it happens.