No, it won’t. Successfully written does not mean what you think it means. If there is “newer” (by timestamp) data on disk or in memtable then it will not be returned to a client, regardless of which order that data arrived. It is unlikely even to be written to disk (except the commit log).
Since at least one of those nodes has the “newer” value, only one node can serve this “older” value
Since at least one of those nodes has the “newer” value, only one node can serve this “older” value