since jack has never really participated in any line-wide events, here's some little headcanons as to what he was up to during the greatest hits:
secret wars (1984): jack did not participate in the all the mayhem on battleworld, but did try to step up and pick up some of the slack that the missing heroes left behind. for those few months, he was more or less the main superhero of los angeles.
mutant massacre: jack did not participate in mutant massacre, but the morlok tunnels eventually became the site of monster metropolis, which would be relevant to him later.
infinity gauntlet: he was among the half of heroes snapped away, and eventually restored to life.
onslaught: you know he wouldn't touch that shit with a ten foot pole.
civil war: this is where things get interesting. jack was nominally pro-registration due to his history with iron man. the werewolf's animal abilities were put to work tracking down some anti-reg holdouts. he was stark's envoy to the marvel monsters, who he could not convince to join the fighting. when goliath was killed, jack ended all of his involvement in the civil war.
secret invasion: the werewolf was able to sniff out skrulls, and it and the marvel monsters did some battle against them. jack was on the periphery, just off screen, during the central park battle.
dark reign/siege: after norman osborn assumed the levers of power, HAMMER went after the marvel monsters, jack included. he had a particularly nasty, knock down, drag out wolf fight with daken. monster metropolis was being established at this time, and when daken hacked frank castle into pieces, jack was among the monsters who gave him his... new lease on life
avengers vs x-men: see onslaught
secret wars (2015): jack was on earth when the incursion with the ultimate universe happened, and was briefly erased from existence
civil war II: once again, jack took iron man's side and opposed the exploitation of ulysses, but this time refused to get involved in any way.
secret empire: jack was part of the resistance against hydra and the impostor captain america, hitting the regime guerilla style along the west coast.
blood hunt: always rearing and ready to rip when it comes to all things dracula, he reveled in the chance to fight the vampire menace alongside the avengers and his supernatural buddies.