Here is my guess for Dragonflight.
Plot:
The Champions of Azeroth emerge from the Shadowlands and are met with grave news. Zovaal's attacks on Azeroth's world soul have ripped apart the planet's landmasses, causing a schism far worse than the Shattering. Worse, the Naga had seized the opportunity to mount a full scale invasion of the land, annexing much of the planet. Stormwind and Orgrimmar have fallen and the Alliance and Horde have effectively disbanded with all its leadership stuck in the Shadowlands.
Knights of the Ebon Blade fight against countless hordes of Naga to keep the Citadel defended. When all hope seems to be lost, Alexstrasza swoops in and blasts the Naga hordes with searing dragonfire. She and her Red Dragonflight ferry the remaining survivors to the Dragon Isles where they are met by Magni Bronzebeard - it is there that they learn that Alexstrasza is the only remaining Dragon Aspect and had been working on bringing as many survivors as she could to her sanctum.
Magni laments that Azeroth's world soul had been mortally wounded and that there is no hope of saving her. Bolvar then has a sudden thought. "Let's go to the Caverns of Time and fix the timeline," he exclaims, only for Alexstrasza to shake her head.
"The Naga control Tanaris. They besieged the Caverns and slain Nozdormu!"
Bolvar sighs. "We must take those caverns back. They're our only ho..."
"We're struggling to hold out here," Alexstrasza snaps. "If we leave, the Dragon Isles fall, and so does everybody else!"
All of a sudden, a portal opens up behind them and a familiar face emerges along with a legion of black and white drakes... it's Murozond.
Everybody draws their weapons, ready to beat back the intruder, before he clicks his fingers and stops everybody in their tracks, freezing them in time. Only Alexstrasza is unaffected.
"Came to finish the job? Then go ahead! Strike me down! But I won't go down without a fight."
"Calm yourself, Alexstrasza," Murozond bellows. "We are not here to fight. We are here to help you."
"Help? You tried to change history for the worse!" she snapped. "You tried to kill Thrall, to kill Medivh, to kill Arthas, to surrender Azeroth to the Burning Legion!"
"We were trying to save her!"
Alexstrasza stops, speechless at what her nemesis had said.
"Azeroth is our only hope. We are here to help you save her. Let us guide your forces through the timelines."
Murozond clicks his fingers again, and the room returns to normal. Everybody lowers their weapons.
"Are you sure this is a good idea?" Khadgar asks.
"We have no other choice," Bolvar replies. "Champions, to arms. We must venture forth through the passages of time and save our world!"
Everybody cheers, and the World of Warcraft: Dragonfight logo pops up.
Features:
- Level cap increased to 70.
- New starting zone experience, level from 1 to 70 in the Dragon Isles, which features 7 distinct zones.
- Endgame focused around time travel to various zones across Azeroth's history.
- Mythic+ seasons are more frequent and now feature a rotation of dungeons across all points in WoW's history: from Classic to Dragonflight.
- Timewalking is a permanent feature.
- Chromie Time (to return to Classic or Shattering-era Azeroth and level in any past expansion) remains available for players who already have a max level character.
- Talent system overhaul. Talent trees are brought back, except every class has a shared tree for all their Specializations.
- New Hero Class: Tinker (Mail DPS/Tank.)
- New specializations for each class, aside from Druid: Rogue (tank), Hunter (tank), Shaman (tank), Mage (healer), Death Knight (ranged DPS), Paladin (ranged DPS), Warlock (tank), Demon Hunter (ranged DPS), Warrior (healer) and Priest (tank.) Every class can either tank, heal or both.
- Race/Class combinations abolished. Any race can now be any class.
- Factions are abolished, as the Alliance and Horde have broken apart. These players can now play with each other without restrictions.
- Arena and Rated Battleground overhaul with solo queue matchmaking.
- Seasonal raid rotation, with a mix of past and current raids tuned to max level, with new affixes.