Yes, you're right that teams still have poke, but an only-poke team won't auto-win like on ARAM.
The snowballs in ARAM have less than half the range of those in LotPK, and the King itself warps the meta due to its use for both sustain and the ability to readily drop aggro through the summoner "to the King."
Yes, poke champs are still really really good, but diving champs who would often be rerolled on ARAM are picked in Poro King due to the forced summoner spells making it harder for the enemy carries and poke champs to escape their dive (they have no flash and Lux doesn't really want to snowball in for obvious reasons)
Here is data on top champs in both modes:
ARAM data:
https://lolalytics.com/aram/worldwide/platinum/plus/detailed/
Poro King:
https://lolalytics.com/poroking/worldwide/platinum/plus/detailed/
Anything OP on ARAM but immobile drops in winrate by quite a few notches in LotPK.