Delays are bound to happen in product releases even at the best of times. Right now? It's just kinda nice when some things are only delayed by a couple weeks. That's what happened with some of March's releases from Paizo, but they're available now.
From the website:
March’s new releases rolled to April 7 but are worth the wait; they include Bestiary 3 with over 300 creatures, an unwelcome turn of events in Crash and Burn, and a relic left behind by one of the Outer Gods in Eyes of Empty Death!