This is where things get tricky. Every customer has their own "application" - especially in the data center where Google doesn't necessarily want to share their secret algorithm sauce with Facebook for example.
I believe this is the main reason Intel wants to get into FPGA so they offer some HW programmability/customizability to their customers.
For other applications where they need more performance/tighter memory integration, they may decide to go full ASIC and/or integrate custom logic with something more flexible like ARM SOC substrates.