I could be wrong, but I believe they do have to pay that $10M. If you look at the RFP on page 6 it says:
"As stated above, the City-owned land consists of two parcels with the City’s Priest Yard on Maricopa County Assessor Parcel No. 124-27-013. This parcel is subject to certain rights pursuant to that certain Development and Disposition Agreement (Multiple Parcels Near the Corner of Rio Salado Parkway and Priest Drive) dated February 14, 2013 and recorded on March 18, 2013 as Maricopa County Official Recorder’s No. 20130246646. The aforementioned rights are currently held by Verde Investments, Inc., an Arizona corporation, pursuant to that certain Assignment and Assumption of Interest in Development and Disposition Agreement dated August 2, 2019 and recorded on August 2, 2019 as Maricopa County Official Recorder’s No. 20190592025. The proposal must include respondent’s plan for acquisition of this parcel, proposed financing for doing so and acquiescence from Verde Investments, Inc., or current entity that holds the aforementioned rights"
https://www.tempe.gov/home/showpublisheddocument/91767/637662016119370000
It is also listed in the DDA as part of the bond as you can see in the attached picture.