Here is an excerpt from the FAQ.
6. What is an Eligible Night?
For the purpose of this promotion, an “Eligible Night” is defined as any night during the promotion period where a member is paying an Eligible Rate or redeems a free night award.
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11. Are there any restrictions on the form of payment in order to participate in this promotion?
Eligible methods of payment include cash, Points + Cash, check, or major credit cards or debit/bank cards. Eligible methods of payment exclude, without limitation, hotel “House Accounts,” charges settled by a company or organization, charges billed to a guest room/folio or unit at a Hyatt-branded residence, Hyatt-branded gift cards, Hyatt gift cheques, or property-specific gift card/certificates.
Would a points redemption be a "free night award" in FAQ 6? Would a Free Night Certificate redemption be a "free night award" in FAQ 6? It seems odd that FAQ 11 specifically mentions Points + Cash but does not mention points only, and that neither FAQ 6 nor FAQ 11 mentions a Free Night Certificate, especially since FAQ 11 specifically excludes Hyatt-branded gift cards. (It seems like a Hyatt-branded gift card and a Free Night Certificate would be similar forms of Hyatt currency, as would other excluded payment methods, but then points are a Hyatt currency, and Points + Cash is allowed.)