To say that WWE is good at building up PPVs beforehand nowadays would be a bit of a lie. Even last night on a stacked card, they still had an impromptu match and one that had no build.
That said, all of that thought should go out the window for WrestleMania. This is the one night where you do not skimp on the card. Every match must have some meaning or at least be marketable.
While WWE has seven weeks to build the remainder of the card, they need to start right now in convincing everyone that the matches on the card mean something. The less thrown together matches, the better.
Every week counts, so the WWE cannot and hopefully will not fail now.