No, You can generate loan offers for a particular vehicle even if you have not made a final decision yet. You can select the vehicle that you would like to generate loan offers for during your Tenet Application. And then update the vehicle on your application, and see the updated offers associated with it.
Note: For new purchase loans, If you initially applied indicating the Vehicle will be purchased directly from Tesla, Rivian, or Lucid, and then later change the purchase source from OEM to Franchise or Independent Dealership, you will need to reconsent to a new Soft Credit Check, as Credit Eligibility Requirements differ for Loans purchased directly from OEM, then a Dealership.