H1B Question

The lawyers my new company are hiring just submitted my H1B application. I thought they should ask my signature on the finalized paper forms. But they didn't. I called them, they said I already signed
a form to agree them to deal with the paperwork for me(I did sign a from to give the permission before they started my case), so I don't need to sign on the finalized paperwork. Is that true? Anybody has similar experience? Thank you for your input.