Parasites and disease pose possibly irresolvable challenges. One parasite,Parelaphostrongylus tenuis, popularly known as "brainworm," lives in white-tailed deer without harm, but can infect moose, where it causes a hideous death. The deer reach their northern limits in Ontario while the moose reach the southern limit of their own range. Where they overlap, moose often die from brainworm infections. The brainworm can't survive on moose alone, since the parasites die, so they are restricted to where the deer live.
Limits to other anthropogenic change deleterious to moose come with what I suspect is too high a political cost. Destructive logging, mining, resource extraction, industrial activities, and such recreational events as snowmobiling will continue - to the detriment of moose habitat.
Bears normally don't kill and eat moose, but can sometimes kill calves, and certainly eat carrion (typically before the hunting season opens), while wolves tend to take moose prey in the winter, after the hunting season ends.