Database
[{_id:ObjectId("638f5f7fe881c670052a9d08"),theList:[{propertyToUpdate:"oldValueToAssign",time:ISODate("2022-11-22T06:30:49.000Z")},{propertyToUpdate:"oldValueToAssign",time:ISODate("2022-11-25T15:30:00.000Z")}]},{_id:ObjectId("638f5f7fe881c670052a9d09"),theList:[{propertyToUpdate:"oldValueToAssign",time:ISODate("2022-11-22T09:29:45.000Z")},{propertyToUpdate:"oldValueToAssign",time:ISODate("2022-11-23T19:26:00.000Z")}]}]
Query
db.collection.update({_id:ObjectId("638f5f7fe881c670052a9d08")},[{$set:{theList:{$concatArrays:[{$slice:["$theList",0,{$subtract:[{$size:"$theList"},1]}]},[{$mergeObjects:[{$last:"$theList"},{propertyToUpdate:"NewValueToAssign"}]}]]}}}])