I don't know any major service at FB that works this way. There could be risks from increased uptime, but I don't know any service that has OOMing as a regular, expected behaviour.

Memory is big enough an issue that they have a whole team working on jemalloc internally. It’s a big enough issue that, when a release of jemalloc messed up the memory usage profile on my team’s service, one of my team mates spent a couple of months figuring out why.

That sort of cavalier attitude to memory leaks doesn’t really fly when we’re talking potentially millions of dollars in server costs going down the drain.