Going off Gen8 Nat Dex learnsets, all of the following would gain access to Teleport (As low as RU, a couple NU + PU mons do gain access but I don't believe they're worth noting):
There's honestly not a lot but the obvious winners are Clefable, Chansey and Slowbro/King. Clefable we can see just how good it is in SS already but you could probably make a case for it being slightly worse in SM as opposed to SS as it's generally a more offensive meta with more offensive threats. But with that said, Clef can be tailored to doing anything it wants in SM really, it's not forced to run 252+ SDef in this tier. Some ideas I'd imagine would work would be stuff like Clef + Mag to punish steels or pairing it with breakers that longevity (Tapus, Kart, Gren, Vic, Tran, Maw etc)
In regard to the Mag idea, I think it would work very well. It lets Clef put pressure on common counterplay much easier than normal - If you have Tangrowth or Pex out vs Clef then that Clef has a 100% free move here, if you switch out to something like Scizor or Kartana, you run the risk of him Teleporting out to his Scarf Mag and picking them off for free, meanwhile if you switch out to Heatran you run the risk of him getting a Wish off and thats a fully free switchin for his Greninja (as long as tran lacks the right Z) & we all know how dangerous this thing gets when it's kept healthy while your checks are falling apart. Meanwhile if you choose to sit on it with Pex, you cannot stop it from fully healing it's teammates, however Pex is usually safe in this situation provided it has TSpikes but as I mentioned SM has a larger variety of breakers that can fully abuse Pex & Teleport would be insane for enabling this, stuff like Maw doesn't need to risk Scald burns anymore if it wants healed.
I hope that was clear-ish it just started feeling like rambling to me but I was just trying to apply SS Clefable to SM which I do think would be a pretty fucked up addition, it throws traditional counterplay out the window and gives SM's superpowered breakers second lives without resorting to Healing Wish or sketchy normal Wish passing (which opens mons up to getting caught out by random Toxic/burns/para).
As the SS DLC is not out yet, nobody has had a real chance to explore Chansey/Slowbro with Teleport yet, I'd imagine it's going to make things a bit of a shitshow, but I still think Clef is far by the best user