The previous default of CanBeUsedOnAnyThread() proved unsafe since some output devices can safely be used on any thread but cannot safely be used during a crash. CanBeUsedOnAnyThread() was used pre-5.1 to control serialization to an output device during a crash, but optimizations in 5.1 have uncovered that some of these were never safe.
#preflight 62856506614041edb7a6de4b
#rb Zousar.Shaker
#rnx
[CL 20280354 by Devin Doucette in ue5-main branch]
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