You can still get the wrong items in the temple of course, it just means it's outside the temple. Sometimes you even have to go into a temple you can't beat, get an item from a chest, which allows you to get the required item outside, which then finally allows you to beat it.
So within each subarea the candidate items can be distributed.
Now, if they could randomize dungeon maps in the original zelda...
They do, and have for some time.
One interesting thing to note is that some of them have difficulty settings. Certain item dependency chains are more difficult than others, and the locations can be done such that it will always give you easy seeds or always give you hard seeds. Some of them are designed such that you'll always be required to do speedrun tech which are borderline exploits.