Not that Scotty needs it, but it would've been nice if Kirk had anything to say, advice or otherwise, to his third-in-command during his parting speech. But since his ''name'' is during the end credits....
Perhaps Kirk made a series of tapes, to cover different circumstances. For example, if Spock was dead or incapacitated, there may have been a "Scotty/McCoy" version, if Bones were dead, a "Spock/Scotty" version, and so on. I think after a certain point there would just be a generic "To whomever is currently in command" version, in the event that a junior officer like Sulu, Chekov, Desalle, Kyle or Uhura were left in command.