This seems like what I've noticed on MPP systems (a little before cloud): data replicas give a lot more availability than the number of partition events would suggest.

I likely need to read the paper linked, but it's common to have an MPP database lose a node but maintain data availability. CAP applies at various levels, but the notion of availability differs:

1. all nodes available 2. all data available

Redundancy can make #2 a lot more common than #1.