These crashes seem to be a result of increased RAM usage over time (memory leak) ever since the Meet Your Match update. The US servers each have 1.5GB available per server, which no longer seems to be enough (as far as I recall, the maximum they used to reach was around 700-800MB).
We're looking into either upgrading the servers or finding a temporary workaround for issue.
EDIT:
Affected regions are US West, US East, Australia and Europe. The Singapore and Russian servers should be unaffected as they have a bit more RAM.