Maybe the Cosmo [animal] is another form of the Gods. We know that Kaldhelm has mDFC, and in some mythologies the gods could come into mortal world into animal form. This is most common in Greek mythology but we did not get a direct equivalent in Theros (looking at you Heliod, how could you not transform into a goose???).
It would be cool if the Gods could be played as a powerfull Cosmos creature that goes rogue or as a god that needs devotion. Also this would make those indestructible gods more relevant as extra copies could potentialy be played.
About the Planeswalkers, i m prety sure they ll not be in Kaldheim. If you look at the site you will see Ravnica miniatures and Zendikar Miniatures that are yet to be released:
It would be cool if the Gods could be played as a powerfull Cosmos creature that goes rogue or as a god that needs devotion. Also this would make those indestructible gods more relevant as extra copies could potentialy be played.
https://www.southernhobby.com/magic-the-gathering-wave-13-unpainted-miniatures-borborygmos-cyclops/p43666/
https://www.southernhobby.com/magic-the-gathering-wave-13-unpainted-miniatures-isperia-law-incarnate-sphinx/p43667/
https://www.southernhobby.com/magic-the-gathering-wave-13-unpainted-miniatures-obzedat-ghost-council/p43665/
https://www.southernhobby.com/magic-the-gathering-wave-13-unpainted-miniatures-rakdos-lord-of-riots-demon/p43664/
https://www.southernhobby.com/magic-the-gathering-wave-13-unpainted-miniatures-goblin-guide-bushwhacker/p43661/
https://www.southernhobby.com/magic-the-gathering-wave-13-unpainted-miniatures-joraga-warcaller-treespeaker-elves/p43662/
https://www.southernhobby.com/magic-the-gathering-wave-13-unpainted-miniatures-stoneforge-mystic-kor-hookmaster-fighter-rogue-wizard/p43658/
https://www.southernhobby.com/magic-the-gathering-wave-13-unpainted-miniatures-vampire-lacerator-hexmage/p43660/
Kaya must be part of the Ravnica stuff while Jace and Nahiri are part of Zendikar stuff