You need to be cautious with recognizing what's a "name". These are usually titles or descriptive label. When you see a webpage, item, link, or document, etc, named that, you should not immediately assume it's a `name=` , especially with these prefixes. Is it "舊羅湖鐵路橋" or "前羅湖鐵路橋"？ Is it "Old" (that's the `name=` added before by others), "Former", or your "Preserved"? This can't be agreed on. Adding these prefixes also interferes with proper names with these words, eg Old Town or Old Market can be a proper name. 
Names should be considered as what will be recorded on nameplates and signs, following the ground truth principle. If the bridge has a plaque, It will be "Lo Wu Bridge" only. Similar to how "Beacon HIll Tunnel" is carved on the previous KCR tunnel, not modified as "Old Beacon Hill Tunnel" etc. 
Another perspective to look at this is how `man_made=` is a physical structure similar to `building=` . This bridge deck has only been moved here. It has no other changes. It's still the same "Lo Wu Bridge". 