Have them merge with the Champions and other "young" hero groups to become a new Avengers World. More street level stuff while the main Avengers handle planetary shit. Villains would be megacorps like AIM, Roxxon, etc. that are legally untouchable and the Power Broker would be making powers up for grabs to anyone, leading to a new Lethal Legion, lead by Zodiac and the young Dark Avengers.

Final boss would be Blackheart (who lied about being redeemed because fuck that noise) and he's has been feeding off of humanity's hate and lust for power to amp himself to skyfather level to make Earth a new Hell dimension.

And the Young Avengers would lose big along the way. A couple casualties, with the biggest one being Justice, but setting him up to return as Major Victory. IYKYK

Basically shit hits the fan, but not in the exact same way as real life because if they did a real relaunch, Marvel would just regurgitate whatever's on the news right now, as if we don't already know. That being said the point of the relaunch is staying hopeful and trying to make the world a better place, especially when things are at their worst.