[{"_id":0,"name":"John","sync_date":"2000-01-01 00:00:00"},{"_id":1,"name":"Paul","sync_date":"2023-01-01 23:23:23"}]

db.collection.aggregate([{$match:{_id:{$in:[0,1,2]}}},{$group:{_id:null,docs:{$push:"$$ROOT"}}},{"$addFields":{records:[{"_id":0,"name":"John","sync_date":"2022-01-01 00:00:00"},{"_id":1,"name":"Paul","sync_date":"2021-11-11 11:11:11"},{"_id":2,"name":"Anna","sync_date":"2012-12-12 12:12:12"}]}},{$unwind:"$records"},{$project:{_id:0,record:"$records",docs:{$filter:{input:"$docs",cond:{$and:[{$eq:["$$this._id","$records._id"]},{$gt:["$$this.sync_date","$records.sync_date"]}]}}}}},{$replaceRoot:{newRoot:{$mergeObjects:["$record",{$first:"$docs"}]}}},{$merge:{into:"collection"}}])