That's correct.
It's not intuitive when you first think about it but you have to treat the GFV for what it is - an offer to purchase the car at a set price. It does not in any way affect the financed amount, as the total credit/finance value is decided by simply subtracting the initial deposit contribution from the total purchase price of the car. The interest is then frontloaded into your monthly payments based of the APR and the length of the agreement, regardless of the GFV amount.
The only way to keep the interest paid the same is to keep your initial deposit at the same level and lower your monthly payments when GFV goes up. However you will still need to find a way of paying that higher GFV at the end of the deal period if you wish to keep the car, and that could mean higher interest re-payments in the future.
EDIT: Higher GFV does protect you from the risk of depreciation, but I don't think anyone considers that likely with the current demand, limited supply and inflation climbing through the roof.