Since $isolated does not work sharded, and it doesn't provide full atomicity that people likely want when they use it, we should deprecate and then remove it once a better option exists.
This ticket depends on and should only be done after SERVER-8538
- depends on
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                    SERVER-8538 Deprecate $atomic/isolated update option -         
- Closed
 
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- is depended on by
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                    SERVER-33529 Ban $isolated and $atomic in local snapshot reads and multistatement transactions -         
- Closed
 
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