That's what it looks like to me, too. I don't find anything in Errata or Sage Advice Compendium that states otherwise.
Damage to a creature on any spot where a fissure opens who fails the Dexterity check would simply take the falling damage for the 10-foot drop, but it doesn't look like the creature would have to worry about any additional damage/restraint, etc., coming from the fissure itself.
The greater potential damage would come from close proximity to a collapsing structure. As a DM, I would rule that a creature inside a fissure would have disadvantage on the Dexterity saving throw to avoid the falling rubble.