In Skyrim (and Fallout 3, although I haven't given 3's leveled lists as close a look as TES games), enemies are replaced by stronger enemies of the same kind as you level up. I don't need to explain how this is ridiculous and inconsistent with the setting. Creature spawns were a bit different most creatures had a static level, but were replaced by higher level creatures (ie Imps would be replaced by Spriggans, then Minotaurs as we level up). They also had leveled gear that would change, so at lower levels you'd see bandits in Fur or Leather armor, but at higher levels they'd spawn in Elven and Glass armor. In Oblivion, level scaling worked by having NPCs level with you at an offset, with min/max levels so a bandit with a minimum level of 6 and an offset of -3 would always be three levels lower than the player, but never go below level 6 regardless of player level.
You could read the sentence as 'we'll have that area blah blah, and then this area blah blah', but I guess we'd need to know the tone he said it with to be sure.