To be clear, I mean close Asura to new account creation or transfer, not break it up and force people elsewhere. The former is not uncommon to see. I think XI did it earlier on, or some form of it - couldn't pick your server outside of a World Pass.
XIV does it now.
Granted, it'd be kinda too little too late for XI. Again, I think SE is just deliberately hands-off at this point. Were they to take a more active role in managing server populations and do merges, then I'd expect limitations to be placed on Asura as well. It's just that much larger than any other server (19.6k active to Odin's 12.5k per the FFXIAH database).