Nope. Any takedown notice or C&D that can't even keep straight whether it's talking about trademarks or copyrights is an empty threat. If this kind of thing were sent by a lawyer, that lawyer would need to be disbarred. There's just no room here for another side of the story to demonstrate some kind of competence on the part of GoPro.
"This letter was sent because DigitalRev is not an authorized reseller of GoPro products and they were using images and had incorrect branding and representation of our product in their online commerce store."
(No representation is made herein as to the validity or invalidity of this side of the story.)
Unless someone has the actual story. There may have been infringing content.