Mages
Strong and versatile in solo/duo/group PvP/PvE as is so not much has been changed.
Not the most efficient at farming instanced zones but still capable of doing that.
Not the best at Grand Olympiad.
Effective early on without much gear investment.
Archers
Improved PvE efficiency and PvP comfort.
AoE skills reworked for better PvE capability, e.g., Burst Shot is acquired earlier.
Various new trigger(counter) skills to improve PvE and PvP.
Not very good at solo (though some single target abilities have been improved), most effective in a full party.
Even worse at Grand Olympiad.
Very gear dependent.
Melee (Tanks, Rogues, Warriors)
Boosted to oblivion.
New and improved skills.
Improved AoE capabilities.
Excel at instanced zones.
Dwarves absolutely destroy everything at early stages but get outmatched later on.
Tyrants and Gladiators are late bloomers. Same for Rogues.
Tanks are always relevant but severely underestimated.
Fine at Grand Olympiad, less for Warlords, more for Dwarves (early on).
Very gear dependent.
Summoners
Not a meta archetype, only for those who enjoy the playstyle.
Combat transformations added to imitate capabilities of other classes (Warlock - Archer, Elemental Summoner - Mage, Phantom Summoner - Rogue).
Good at solo and instanced zones.
Good at Grand Olympiad.
Still a work in progress, more changes to come.
Bards (Blade Dancer, Sword Singer)
Dance and Song skills are combined into Rhythms that last 5 minutes so a party only needs one bard to be efficient.
Added new passives for mana management and weapon passives for Daggers and Bows.
Mandatory for instanced zones.
Fine at Grand Olympiad.
Welcome in every group but also very good at solo.
Not gear dependent (except for solo).
Best starting class for solo players or those who wants to find a group in the future.
Support (Enchanters, Healers)
Improved solo PvE (PvE attack skills added outside of combat transformation).
Earlier skill acquisition.
Mandatory for most group activities.
Judicator damage nerfed (can be a main class since previous season).
The video mostly briefly explains the contents of this thread:
But the changes for MW 2022 are not going to be limited to just that. Thy just haven't completed the skill rework for the new season yet. The new balance changes are to be announced prior to the open beta test in November.