With Singapore on the server it seems a part is missing. Malaysia is quite the fun world to explore and while on GMS was added post v.62 it was added early on in MSEA and other Asian official servers so for many of them it would be nostalgic to play on Malaysia.
This has been discussed before and the majority of the community came to the conclusion that Malaysia would make a good chunk of content dead like Zakum Helmets and training locations from 80-130.
You can always nerf the Malaysia helms or remove them. Also you can buff the other training spots so they are similar to Malaysia. Besides Singapore pretty much becomes the top training spot from 50. Malaysia can be just another option in the game that could add variety.
Rebalance the entire game around a small amount of new content being released? Do you realise how nonsensical this sounds?
I think this would be a great addition to royals. Like any other future additions, It will need some nerfing/balancing.
How? Wouldn't people like to have the ability to have a back up helmet to scroll? And besides, Zhelms are lvl 50, scar hats are lvl 80, and Zakum gives a lot better exp and drops. I'm quite sure Zakum wouldn't die. Training locations are never dead, it just gives people more map options besides WS, Himes, Ulu City, or Skeles.
If you provide an option to players on a training location that is head over heels above the competition in terms of XP (and don't even get me started on the drops), believe that there will be abandoned locations.