There are a number of issues built into your question.
First, if the transaction meets certain criteria a risked-based pricing notice is needed unless a credit score notice is provided. A risk-based pricing notice is not required for a denied application. So a credit score notice is not required for a denied application. It is OK to still send one.
15 USC 1681(g) of the FCRA established the requirements for credit score disclosures. It does not address electronic disclosures. There are no implementing regulations for that section of the law. If electronic disclosures are used, compliance with E-Sign is advised.
15 USC1681(m) of the FCRA established the requirements for risk-based pricing notices. It does not mention electronic disclosures. Section 1022.73(b)(1) of Regulation V implements the risk-based pricing notice rules. It allows electronic disclosures, but does not mention E-Sign. Compliance with E-Sign is not required.