Hyatt Gold Passport - When do we get the new gold passport bonus point offers?

I'm looking to do bookings in December but these offers extend only until Nov 30. Could I add the code to the reservation afterwards? Are we likely to get new offers before Nov 20?

You can always add the code later at several time points - before the stay (call CS), at check in and check out (before they close the folio), and if all of that fails you can call CS after your stay and they will add the points.

RE your second question, we will probably see the new list by Nov 20 but it is not guaranteed.

Having the code in the reservation prior to the stay doesn't really do much - since its not likely to post unless its added at check-in/out - so don't worry about it.