Database
[{_id:ObjectId("638f5f7fe881c670052a9d08"),list:[{propertyToUpdate:"oldValueToAssign",time:ISODate("2022-11-22T06:30:49.000Z")},{propertyToUpdate:"oldValueToAssign",time:ISODate("2022-11-25T15:30:00.000Z")}]}]
Query
db.collection.update({_id:ObjectId("638f5f7fe881c670052a9d08")},[{$set:{list:{$concatArrays:[{$cond:[{$gt:[{$size:{$ifNull:["$list",[]]}},1]},{$slice:["$list",0,{$subtract:[{$size:"$list"},1]}]},[]]},[{$mergeObjects:[{$ifNull:[{$last:"$list"},{}]},{propertyToUpdate:"NewValueToAssign"}]}]]}}}])