That is true for every OEM. It is explicitly against policy for most dealers to "upsell warranty work" unless it is a safety issue or may cause a mechanical breakdown.I heard years ago that Ford dealers were instructed not to fix anything under warranty unless the customer complained about it.
Furthermore, dealers with "excessively high" amounts of warranty work were scrutinized by Ford.
And on top of all that, warranty work was paid at a lesser rate than customer-pay work.
All of which made getting warranty work done at a Ford dealer that much more difficult for the customer.
No idea if any of that is still the case. I haven't owned a Ford under a factory warranty in over 20 years...