After reading over the archetype, you are correct and incorrect. Expanded Wishcraft does not modify the spells that a sorcerer gets normally. So at level 3 a sorcerer will have 3 1st level spells as noted on the class table.
However, Expanded Wishcraft does modify the BONUS spell the sorcerer gets from their bloodline. So at level 3 when they would normally get a specific 1st level spell they cannot choose, like Enlarge Person for the Abberant Bloodline or Mage Armor for Draconic, they get a 0 level spell of their choosing.
At lower level this can be kinda blah, but when you get access to a 5th, 6th, 7th, and 8th level spell of your choice, it kinda works out.
So a 3rd level Sorcerer of normal variety will have:
5 0 level spells known
3 +1 1st level known (where the +1 is a predetermined bloodline spell)
A Wishcrafter Sorcerer will have:
5 +1 0 level spells known (where the +1 is a player chosen spell)
3 1st level spells
*Edit Ignore me, looks like I just explained what you already said.