Section 1005.4(a)(1) says "the disclosures required by this part may be provided to the consumer in electronic form, subject to compliance with the consumer-consent and other applicable provisions of (ESIGN)." If post-notice-on-website was included in your preconsent disclosures and tested as part of the "test drive" accompanying the act of consenting, then you're covered. The fact that you're asking this question suggests that this delivery method is an afterthought or a unilateral change.
_________________________
...gone fishing.