Hilton brand standards (for actual Hilton hotels, not sure about the other brands in the family) specifically states in section 8.3.3:
For Gold and Diamond VIP Members, the credit card information should be retrieved from the guest’s HHonors Profile / Reservation and verified with the guest that they would like to use the same credit card on file. Gold and Diamond VIP Members who have a valid credit card on their reservation record or eCheck-In ARE NOT required to provide a credit card or signature at check-in.
The only time I get asked for the credit card is when I'm in Europe. I've never had it happen at any US-based Hilton family property.
Neil