If a multiple is made of a throw, does the multiple have the throw attribute?

No, any multiples that are created keep everything except for what is in the original attack's text box. The relating rule is emphasized in bold.

2.14.2.4 Multiple
Multiple: X (Enhance) - E Discard up to X momentum: Place the momentum discarded to pay for this ability face down into your card pool to the right of the Multiple attack. Each of the cards placed into your card pool counts as a copy of the Multiple attack with a blank text box and speed and damage values equal to the printed values of the original attack . No control check is required to play these cards, and each copy has its own Enhance Phase, Block Step, and Damage Step. Players must go from left to right, resolving each attack in turn. If a multiple copy would go to a player’s momentum for any reason, it is discarded instead. If you attempt to create a “multiple copy” of a “multiple copy,” the “copy of the copy” is discarded.