We've never had this type of tie-in before, correct?
Sure we have. DC Comics was doing their own version of what happened between ST III and ST IV, not knowing whether there'd even be a ST IV. When they knew what the next movie would start with, ie. Spock still pretty much a blank slate, relearning on Vulcan, the comics had several connected issues where Spock and his
USS Surak crew catch a space virus, which kills everyone except Spock, who's mind (which had been restored previously by the Mirror Universe Spock) goes back to the same inert state it was at the end of ST III.
Over on Spacedock, meanwhile, we see Janice Rand (who'd had a ST III cameo in the Spacedock cafeteria) working with outgoing Admiral Morrow (ST III) and incoming Admiral Cartwright (ST IV), plus there's a jubilant Captain Styles plotting the return of his
USS Excelsior, which Kirk and his crew have been using for many months. And they also set up for Kirk and his crew to collect the ailing Spock, and get him to Vulcan again, in the stolen Klingon bird of prey.
None of this was canon. But it certainly set up the anticipation for ST IV for comic readers.