Does Scrap Head draw a card when discarded from Sabotage?

No, Scrapheap does not draw a card when targeted by Sabotage.

Here is the breakdown:

• Sabotage instructs you to recycle a card from your opponent's hand.
• Scrapheap's ability triggers only when it is "played, discarded, or killed."

Because recycling is a distinct game action from discarding (as defined in Rule 403.1 and Rule 409.1), Sabotage does not trigger Scrapheap's ability.