I just saw this scenario play out in the Crystal DC: A fellow hunter of mine and some friends spent the hour completing FATEs on Zalera to spawn the S rank Nuny. When he spawned, one of the notorious S rank early pullers instapulled it and killed it before he could run from where he was on the map and he didn't even get credit. I know this has always been a possibility with S rank spawns even before cross-world hunting, but on my server such players would be kicked from linkshells and generally shunned. There are no such repercussions for cross-world players, so there's basically no incentive for them to stop.

You can say that this is "working as intended," but I don't think it's a good system with these sorts of issues. Throwing all of the players in together means that there's no way for players to "police" the bad behavior and handle it within the community, and since killing an S rank isn't itself a reportable offense, these sorts of players aren't going to stop what they're doing. It leaves hunters that prefer to be cooperate and inclusive (which is most hunters in my experience) with their hands completely tied and many have vented their frustrations in chat over the past several days.