I agree with a lot of what you’ve said, but I have some things to say about your choices. It’s important to distinguish between the cards that prop up an archetype on account of their power and cards that define an archetype based on their mechanics.
Lucent Beam and Sun Wisp are sort of filler cards for their respective archetypes that could be replaced by new additions. Afterblaze (and Ironcliffe Heart to an extent) is an important card for Brome and also for establishing Zeal synergies as a thing beyond “this card is pretty strong next to your General.”
Katara, Battle Pando, and Ki Beholder are all strong cards, but not archetype enablers. They’re just slightly powercreeped versions of things that already existed, and won’t harm Songhai in the long run when they leave. Crescent Spear is an archetype enabler for Spell Damage Controlhai, and Onyx Jaguar is a great enabler for another Controlhai build focused on movement procs. A serious shame that these two unique cards are going to be lost.
Falcius and Pax are strong, but only because their power levels are so high. Psychic Conduit was another important card for Cypheron, though the expansion will probably remedy this. Whisper of the Sands is definitely a central card for Aggro Obelysks, and a huge loss to the archetype. Spinecleaver was equally crucial for Control Artivet.
The loss of Abyssian’s Creep cards is not actually that bad: Obliterate and Azalea were limiting design space in terms of Creep generation and utilization. Ooz has long been a staple in Abyssian not because it generated Creep but because it was the only decent Abyssian 2 drop. Klaxon is a sad loss for Dying Wish decks and a solid card all around that never did nothing wrong, but its not a major loss. Same for Gor and Sphere; solid, fun cards, but not game breaking. The WORST for Abyssian is the loss of Lurking Fear. Such a fun archetype down the drain if this card isn’t salvaged. (hint hint Counterplay: Wraithling Fury isn’t doing much in the Epic spell slot)
Magmar’s loss of Moloki is MASSIVE. Even without Gro, Growmar could’ve continued on as long as they didn’t lose Moloki. Morin Khur and Wild Inceptor were also important cards, although not quite as gamebreaking to lose as the Huntress; I’m certain Ragnora will have the pressure come expansion time to make a non-combo based Egg deck viable.
Finally, Vanar loses… not much besides Winter’s Wake. Wall Vanar will lose their big enabler, which is sad, but Vespyr synergies will bounce back.
IMO, the major losses this expansion are definitely Moloki Huntress and Lurking Fear.
Archetypes getting neutered: Combo Eggmar, Control Artivet, Spell Damage Controlhai, Onyx Jaguarhai, Growmar, Lurking Abyss, Wall Vanar, Creep Abyss, Aggro Dervet, anything with Battlepets (obviously)