When using classic update language with operators $set, $pop, $pull to add/remove an element from the array, it writes down the new value of the array to the oplog, and leads to large change stream events.

Instead we could use compact diff so that the resulting change stream event would include:

{ updateDescription: { updatedFields: { 'arrayField.3': 4  }, ...  }}

or 

{{{ updateDescription: {..., truncatedArrays: [ { field: 'arrayField', newSize: 3 } ] } } }}