i wish they would do something like that today, they haven't added a new, sizable area in ages.
This is a problem with current RS because everything in the game has grown, yet the world stays the same size; every NPC and area looks so special and detailed, yet they're all within ten metres of eachother.
it works in OSRS because the world is built using a certain amount of objects, almost never creating new buildings or NPCs for new areas; e.g.; in OSRS you can look like an NPC, and NPCs look like you. Most NPCs wear clothing that you could wear, or at least re-coloured clothing that you could wear. It makes you feel more like a part of the world. Buildings and terrain are also built using a few different objects, making the theme more consistant and apparent.
In modern RS, every NPC and thing has its own model, making you and your items look out of place. it's also more notable how close things are to eachother. Englarging trees while keeping forests the same size makes forests look smaller, and towns have completely separate styles. Keeping almost every activity besides minigames and quests to three or four cities doesn't help either, and since you can run constantly, teleports become useless (not to mention lodestones making magic useless in the first place) and the world shrinks even more.
The world needs to be upscaled and enlarged to make it work.