Wong (10-2 vs. 4)

Wong states in Professional Blackjack on page 23 the following:

"If you get to twelve by 10-2 or 2-10 (where 10 means any 10-count card), and two or fewer decks are being used (or seven or fewer if the dealer stands on soft seventeen), you should hit."

Is that correct?

I can see it for a one or two deck game where composition-dependent strategy has a certain amount of value to it, but he's saying that you should hit a 10-2/2-10 when SEVEN decks are used (S17)!

That doesn't sound right to me.

Is there a typo in the book? Should it say "...if the dealer HITS on soft seventeen"?