The new errata says:
when you are told to get a card from your discard pile, if it's not on top, or the card is chosen, you can look through your discard pile to get the card. You don't get to look through your discard pile to take the top card (again unless you're choosing a card from your discard pile).
I figured this meant that one of the new cards in Menagerie would have some sort of "trash a card from your discard pile" effect or something, and the errata was so that it didn't need to have "you may look through your discard pile".
Now there's March:
Look through your discard pile.
You may play an Action card from it.
With the errata, why not just "you may play an action card from your discard pile"? Or alternatively, why have the errata talk about choosing a card from your discard pile implicitly allowing you to look through it if the new card that has you choose a card from your discard pile has that wording anyway?