Ok so I posted a thread about this issue and stated it was minor and confined to just map enemies, now it has become apparent that this issue is much more widespread than I initially thought. You can check out my first post HERE.
So now not only do enemies not respawn in FH 1-4 and Wyldwood (probably any other map that has an infinite amount of enemies and no remining counter), but bosses that have respawning items to preserve themselves (Gold Fever, Cockroach, Goblin King). These items also don't respawn making them quite a bit harder. Initially I thought it would be awesome that they couldn't replenish their health, but it seems that even though these items are not visible they're still in play.
GF still can cause fever, and has his green rings. This seems to make him a bit more resilient to attacks:
GK still stands in his regen stance surrounded by green aura, and gains his health even though the totem isn't available for attack:
I have yet to see Cockroach just gain life without the cans, but I'm not sure that if he isn't killing in a timely fashion that he may just rage out and fully gain his health like GK.
This could also be the reason that firetraps are not working too (though I like that one), I don't know the inner workings of the game but firetraps could just be respawned bursts of AoE damage in a certain areas. There are not traps that are visible at the start of any map, but it's possible they all go off at once during start up and without respawn they cannot go off again.
I hope that this is just a small issue that can be fixed server side, and not require an update to be sent to Apple. If anyone else has confirmed pics of Cockroach gaining health after the cans have been destroyed please post them, it's the only one that I couldn't actually confirm.