Based on the wiki, Cam Skattebo does not appear to have been injured by the botched backflip at Fanatics Fest. The article title — "Cam Skattebo’s failed Fanatics Fest backflip tempts fate" — suggests it was a close call rather than an actual injury (from the John Harbaugh page). His July 16 medical update notes he's already been "observed doing backflips at charity softball games" this offseason and is expected to play Week 1 with no limitations (from the Cam Skattebo page).
That said, the experts definitely took note of it. On Establish The Run, Evan Silva said he watched the video closely: "I didn't like the way that he tried to stick the landing. I didn't like his landing on the back..." — . And Late-Round Fantasy Football called it a red flag: "That is a lot of force on that leg... that was really all I needed to see" — . So it's more of a "yikes, that was risky" moment than an actual injury setback.