Pretty much yes. The only one I'm not 100% on (besides the scout skin, since that was after I stopped playing) is the engineer prosthetic. I feel like that weapon came out a while after TF2 was made (but I can't check that right now so don't take my word for it).
Jarate and heavy x medic were after release too afaik.
Heavy x medic was kinda obvious, but iirc valve didn't start dropping stronger hints until the past few years. Dunno if they've straight-up confirmed it yet or not; it's also been a while since I last played.
Jarate was part of the sniper update, which I thought came after release (because iirc there weren't any alternate items in the original release).
One of the Engineer's unlockable weapons is the Gunslinger which is a prosthetic hand. It also is (or was) commonly regarded as OP since it replaced the turret with a fast self-building mini-turret that was a pain to keep destroyed (Engie would toss out another one).
im so glad that all of these WOKE LIBERAL SOCIALIST things are out of the game as it was released back in the GOOD days before EVIL GAY PEOPLE were in my videogames,. thank you gabe newell for making gaming real 🙏